Corrigendum: Facile Synthesis of Sequence-Regulated Synthetic Polymers Using Orthogonal SuFEx and CuAAC Click Reactions.
PMID: 30614641 [PubMed - in process] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 9, 2019 Category: Chemistry Authors: Yang C, Flynn JP, Niu J Tags: Angew Chem Int Ed Engl Source Type: research

Spotlights on our sister journals: Angew. Chem. Int. Ed. 3/2019.
Authors: PMID: 30614642 [PubMed - in process] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 9, 2019 Category: Chemistry Tags: Angew Chem Int Ed Engl Source Type: research

Interplay Between H-bonding and Preorganization in the Evolution of Self-Assembled Systems.
z G Abstract Cooperative π-π-interactions and H-bonding are frequently exploited in supramolecular polymerization, however, close scrutiny of their mutual interplay has been largely overlooked. Herein, we compare the self-assembly behavior of a series of C2- and C3-symmetrical oligophenyleneethynylenes differing in the amide topology (N- or C-centred). This subtle structural modification brings about drastic changes in their photopysical and supramolecular properties, highlighting the reciprocal impact of H-bonding vs. preorganization on the evolution and final outcome of supramolecular systems. PMID: 3...
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Philips DS, Kartha KK, Politi A, Krüger T, Albuquerque RQ, Fernandez G Tags: Angew Chem Int Ed Engl Source Type: research

Regiodivergent Hydroaminoalkylation of Alkynes and Allenes via a Combined Rhodium and Photoredox Catalytic System.
Abstract A rhodium/photoredox dual catalyzed regiodivergent α-allylation of amines is described. As an atom-economic and efficient method, alkynes and allenes are used as allylic electrophile surrogates in this novel protocol. With different reaction conditions, synthetic useful branched or linear homoallylic amines could be synthesized in good to excellent yields and regioselectivity. This straightforward strategy complements the traditional transition-metal catalyzed allylation reactions. PMID: 30620131 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Breit B, Zheng J Tags: Angew Chem Int Ed Engl Source Type: research

Elusive Zintl Ions [ µ HSi4]3- and [Si5]2- in Liquid Ammonia: Protonation States, Sites, and Bonding Situation by NMR and Theory.
Elusive Zintl Ions [µ HSi4]3- and [Si5]2- in Liquid Ammonia: Protonation States, Sites, and Bonding Situation by NMR and Theory. Angew Chem Int Ed Engl. 2019 Jan 08;: Authors: Hastreiter F, Lorenz C, Hioe J, Gärtner S, Nanjundappa L, Korber N, Gschwind RM Abstract They are detected! The existence of the elusive and stunning [µ HSi4]3- anion in liquid ammonia solutions could unambiguously be proven by diverse 1H and 29Si NMR experiments. Both, NMR and Quantum Chemical Calculations reveal that the hydrogen atom bridges two silicon atoms of the [Si4]4- cluster contrary to expectations th...
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Hastreiter F, Lorenz C, Hioe J, Gärtner S, Nanjundappa L, Korber N, Gschwind RM Tags: Angew Chem Int Ed Engl Source Type: research

From As-Zincoarsasilene (LZn-As=SiL') to Arsaethynolato (As ≡C-O) and Arsaketenylido (O=C=As) Zinc Complexes.
From As-Zincoarsasilene (LZn-As=SiL') to Arsaethynolato (As≡C-O) and Arsaketenylido (O=C=As) Zinc Complexes. Angew Chem Int Ed Engl. 2019 Jan 08;: Authors: Driess M, Ballestero-Martínez E, Szilvási T, Hadlington T Abstract The reactivity of the As-zincosilaarsene LZn-As=SiL´ A (L = [CH(CMeNDipp)2], Dipp = 2,6-iPr2C6H3, L´ = [{C(H)N(2,6-iPr2-C6H3)}2]2-) towards small molecules has been investigated. Due to the pronounced zwitterionic character of the Si=As bond of A, it readily undergoes facile addition reactions with H2O and NH3, in forming LZnAs(H)SiOH(L´) 1 and ...
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Driess M, Ballestero-Martínez E, Szilvási T, Hadlington T Tags: Angew Chem Int Ed Engl Source Type: research

Energetic basis of AGCGA-rich DNA folding into a tetrahelical structure.
In conclusion, we show that AGCGA-quadruplexes have a distinguishing thermodynamic fingerprint and that the corresponding driving forces enabling their folding are consistent with the observed structural features. PMID: 30620431 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Hadži S, Kocman V, Oblak D, Plavec J, Lah J Tags: Angew Chem Int Ed Engl Source Type: research

A New Class of Heteroatom-Doped Porous Carbon Materials with Unprecedented High Volumetric Capacitive Performance.
Abstract The design of simultaneously high mass density and large porosity carbon-based materials has always been a challenging goal to fulfill the demands of next generation of high volumetric performance supercapacitors and other electrochemical devices. Here, we report a new class of high-density heteroatom-doped porous carbon as aqueous-based supercapacitor materials via an in-situ dehalogenation reaction between halogenated conjugated diene and nitrogen-containing nucleophiles. Under reaction conditions, pyridinium salts with conjugated double bonds could continue to experience the dehalogenation reaction onl...
Source: Angewandte Chemie - January 8, 2019 Category: Chemistry Authors: Jin H, Feng X, Li J, Li M, Xia Y, Yuan Y, Yang C, Dai B, Lin Z, Wang J, Wang S, Lu J Tags: Angew Chem Int Ed Engl Source Type: research

Spotlights on our sister journals: Angew. Chem. Int. Ed. 2/2019.
Authors: PMID: 30609085 [PubMed - in process] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 6, 2019 Category: Chemistry Tags: Angew Chem Int Ed Engl Source Type: research

In vitro reconstitution of bacterial DMSP biosynthesis.
In this report we provide the first complete description of a DMSP biosynthetic pathway by in vitro reconstitution of four enzymes from Streptomyces mobaraensis. Isolation of DMSP in S. mobaraensis grown at high salinity confirmed that this actinobacterium is indeed is a DMSP producing organism. This biosynthesis follows same route as previously described in angiosperm plants. Despite this chemical congruence, limited sequence similarity between plant and bacterial enzymes suggests that that the two biosynthetic activities emerged independently. PMID: 30609124 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 4, 2019 Category: Chemistry Authors: Seebeck FP, Liao C Tags: Angew Chem Int Ed Engl Source Type: research

Double Perovskite LaFexNi1-xO3 Nanorods Enable Efficient Oxygen Evolution Electrocatalysis.
Abstract Perovskite-based electrocatalysts are one of the most promising materials for oxygen evolution reaction (OER), but their activity and durability are still far from desirable. Herein, we demonstrate that the double perovskite LaFexNi1-xO3 (LFNO) nanorods (NRs) can be adopted as highly active and stable OER electrocatalysts. The optimized LFNO-II NRs with Ni/Fe ratio of 8:2 achieve a low overpotential of 302 mV at 10 mA cm-2 and a small Tafel slope of 50 mV dec-1, outperforming those of the commercial Ir/C. The LFNO-II NRs also show high OER stability with slight current decrease after 20 h. The enhanced ac...
Source: Angewandte Chemie - January 4, 2019 Category: Chemistry Authors: Huang X Tags: Angew Chem Int Ed Engl Source Type: research

In-situ Generation of An N-Heterocyclic Carbene-Functionalized Metal-Organic Framework via Postsynthetic Ligand Exchange for Efficient and Selective Hydrosilylation of CO2.
We report a metal-organic framework (MOF) catalyst that realizes the CO2 to methanol transformation under ambient conditions. The MOF is one rare example containing metal-free N-heterocyclic carbene (NHC) moieties, which are installed using an in-situ generation strategy involving the incorporation of an imidazolium bromide-based linker into the MOF by postsynthetic ligand exchange. Importantly, the resultant NHC-functionalized MOF is the first catalyst capable of perform quantitative hydrogen-transfer from silanes to CO2, thus achieving quantitative (>99%) methanol yield. Density functional theory calculations indicate...
Source: Angewandte Chemie - January 4, 2019 Category: Chemistry Authors: Zhang X, Sun J, Wei G, Liu Z, Yang H, Wang K, Fei H Tags: Angew Chem Int Ed Engl Source Type: research

Solid-state Synthesis of Two Different Polymers in a Single Crystal: Miscible Polymer Blend via Topochemical Reaction.
Abstract The topochemical synthesis of a miscible polymer-blend is described here. The azide and alkyne decorated tetrol 1 crystallizes with two different conformers. Both the conformers exhibit self-sorted head-to-tail alignment with proximally placed reacting groups such that topochemical polymerization yields two types of polymer chains each containing only one type of conformers. The orientation of complementary reactive groups in one of the head-to-tail-arranged conformers favors the formation of cis-triazole linkages and the other favors the trans-triazole linkages. Crystals of 1 on heating gave a perfect po...
Source: Angewandte Chemie - January 4, 2019 Category: Chemistry Authors: Sureshan KM, Hema K Tags: Angew Chem Int Ed Engl Source Type: research

Facile Access to a NHC-Coordinated Silicon Ring Compound with a Si=N Group and a Two-Coordinate Silicon Atom.
d C Abstract Reaction of the bicyclo[1.1.0]tetrasilatetraamide Si4{N(SiMe3)Dipp}4 1 (Dipp = 2,6-Diisopropylphenyl) with 5 equiv. of the N-heterocyclic carbene NHCMe4 (1,3,4,5-tetramethyl-imidazol-2-ylidene) affords a bifunctional carbene coordinated four-membered ring compound with a Si=N group and a two-coordinate silicon atom Si4{N(SiMe3)Dipp}2(NHCMe4)2(NDipp) 2. In a reaction of 2 with ¼ equiv sulfur (S8) two sulfur atoms add to the divalent silicon atom in plane and perpendicular to the plane of the Si4 ring which confirms the silylone-character of the two-coordinate silicon atom in 2. PMID: 306049...
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Lips F, Keuter J, Hepp A, Mück-Lichtenfeld C Tags: Angew Chem Int Ed Engl Source Type: research

PhPAd-DalPhos: Ligand-Enabled, Nickel-Catalyzed Cross-Coupling of (Hetero)aryl Electrophiles with Bulky Primary Alkylamines.
Abstract The base metal-catalyzed C-N cross-coupling of bulky alpha,alpha,alpha-trisubstituted primary alkylamines with (hetero)aryl electrophiles represents a challenging and under-developed class of transformations that is of significant potential utility, including in the synthesis of lipophilic active pharmaceutical ingredients. Herein, we report that a new, air-stable Ni(II) pre-catalyst incorporating the optimized ancillary ligand PhPAd-DalPhos enables such transformations of (hetero)aryl chloride, bromide, and tosylate electrophiles to be carried out for the first time with substrate scope rivalling that ac...
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Tassone J, England E, MacQueen P, Ferguson M, Stradiotto M Tags: Angew Chem Int Ed Engl Source Type: research

One-Pot Bioconversion of L-Arabinose to L-Ribulose in an Enzymatic Cascade.
Abstract This work reports the first one-pot enzymatic cascade which completely converts l-arabinose to l-ribulose using four reactions catalyzed by pyranose 2-oxidase (P2O), xylose reductase, formate dehydrogenase and catalase. As the wild-type P2O is specific for oxidation of six-carbon sugars such as d-glucose, a pool of P2O variants were generated based on rational design in order to change the specificity of the enzyme towards oxidation of l-arabinose at the C2-position. The variant T169G was identified as the best candidate, and investigations using transient kinetics indicated that this variant had an appro...
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Chuaboon L, Wongnate T, Punthong P, Kiattisewee C, Lawan N, Hsu CY, Lin CH, Bornscheuer U, Chaiyen P Tags: Angew Chem Int Ed Engl Source Type: research

C ̶ C Bond Formation of Benzyl Alcohols and Alkynes using Catalytic Amount of KOtBu: Unusual Regioselectivity via a Radical Mechanism.
We report the C-C bond-forming reaction of benzyl alcohols and alkynes using a catalytic amount of KOtBu to form α-alkylated ketones in which the C=O group is located on the side derived from the alcohol, a reaction that has not been reported yet in the peer-reviewed literature. The reaction proceeds under thermal condition (125 oC) and produces no waste, making the reaction highly atom-efficient, environmentally benign and sustainable. Based on our mechanistic investigations we propose that the reaction proceeds through radical pathways. PMID: 30605258 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Milstein D, Kumar A, Janes T, Chakraborty S, Daw P, Carmieli R, Diskin-Posner Y Tags: Angew Chem Int Ed Engl Source Type: research

Cu-Mediated Aminoquinoline-Directed Radiofluorination of Aromatic C-H Bonds with K ¹⁸F.
Cu-Mediated Aminoquinoline-Directed Radiofluorination of Aromatic C-H Bonds with K¹⁸F. Angew Chem Int Ed Engl. 2019 Jan 03;: Authors: Lee SJ, Makaravage KJ, Brooks AF, Scott P, Sanford MS Abstract This communication describes a Cu-mediated ortho-C-H radiofluorination of aromatic carboxylic acids that are protected as 8-aminoquinoline benzamides. The method uses K¹⁸F and is compatible with a wide range of functional groups. The reaction is showcased in the high specific activity automated synthesis of the RARβ2 agonist [¹⁸F]AC261066. PMID: 30605563 [PubMed - as supplied b...
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Lee SJ, Makaravage KJ, Brooks AF, Scott P, Sanford MS Tags: Angew Chem Int Ed Engl Source Type: research

Inhibitor-induced dimerization of an essential oxidoreductase from African Trypanosomes.
Abstract Trypanosomal and leishmanial infections claim tens of thousands of lives each year. The metabolism of these single cell eukaryotic parasites differs from the human host and their enzymes thus constitute promising drug targets. Tryparedoxin (Tpx) from Trypanosoma brucei is the essential oxidoreductase in the parasite's hydroperoxide clearance cascade. Functional in vitro and in vivo assays show that a small, selective inhibitor efficiently inhibits Tpx. By X-ray crystallography, SAXS, analytical SEC, SEC-MALS, MD simulations, ITC, and NMR spectroscopy, we show how covalent binding of this monofunctional in...
Source: Angewandte Chemie - January 3, 2019 Category: Chemistry Authors: Wagner A, Le TA, Brennich M, Klein P, Bader N, Diehl E, Paszek D, Weickhmann AK, Dirdjaja N, Krauth-Siegel RL, Engels B, Opatz T, Schindelin H, Hellmich UA Tags: Angew Chem Int Ed Engl Source Type: research

RhIAr/AuIAr' Transmetalation, a Case of Group Exchange Pivoting on Formation of M-M' Bonds via Oxidative Insertion.
acute;a-Melchor M Abstract By combining kinetic experiments, theoretical calculations and microkinetic modelling, we show that the Pf/Rf (C6F5/C6Cl2F3) exchange between [AuPf(AsPh3)] and trans-[RhRf(CO)(AsPh3)2] does not occur through the typical concerted Pf/Rf transmetalation via electron deficient double bridges. Instead, it involves asymmetric oxidative insertion of the RhI complex into the (Ph3As)Au-Pf bond producing a [(Ph3As)Au-RhPfRf(CO)(AsPh3)2] intermediate, followed by isomerization and reductive elimination of [AuRf(AsPh3)]. Interesting differences are found between the LAu-Ar asymmetric oxidative inse...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Espinet P, Peñas-Defrutos MN, Bartolomé C, García-Melchor M Tags: Angew Chem Int Ed Engl Source Type: research

Helicoidal Patterning of Nanorods with Polymer Ligands.
Abstract Chiral packing of ligands on the surface of nanoparticles (NPs) is of fundamental and practical importance, as it determines how NPs interact with each other and with the molecular world. Here, for gold nanorods (NRs) capped with end-grafted nonchiral polymer ligands, we show a new mechanism of chiral surface patterning. Under poor solvency conditions, an originally smooth polymer layer segregates into helicoidally organized surface-pinned micelles (patches). The unique helicoidal morphology is dictated by the polymer grafting density and the ratio of the polymer ligand length-to-nanorod radius, while out...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Galati E, Tao H, Tebbe M, Ansari R, Zhulina E, Rubinstein M, Kumacheva E Tags: Angew Chem Int Ed Engl Source Type: research

Electrochemical Conditioning-Free and Water-Resistance of the hybrid AlCl ₃/MgCl₂/Mg(TFSI)₂ Electrolytes for Rechargeable Mg Batteries.
Electrochemical Conditioning-Free and Water-Resistance of the hybrid AlCl₃/MgCl₂/Mg(TFSI)₂ Electrolytes for Rechargeable Mg Batteries. Angew Chem Int Ed Engl. 2019 Jan 02;: Authors: He Y, Li Q, Yang L, Yang C, Xu D Abstract Rechargeable magnesium batteries are thought of a promising alternative to Li-based energy storage due to the abundant and inexpensive resources. Due to the high sensitivity and reactivity of the organic Mg²+ electrolyte, it is still a challenge to develop high-performance electrolyte. In this studies, we have developed a new hybrid electrolyte, including three simple in...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: He Y, Li Q, Yang L, Yang C, Xu D Tags: Angew Chem Int Ed Engl Source Type: research

Highly Reversible and Safe Zn Rechargeable Batteries Based on Triethyl Phosphate Electrolyte.
Abstract Zinc metal is an attractive anode material for next generation batteries. However, dendrite growth and limited Coulombic efficiency (CE) during cycling are the major roadblocks towards widespread commercialization of batteries employing Zn-anode. In this work, for the first time we report the adoption of triethyl phosphate (TEP) as a sole and co-solvent with aqueous electrolyte to obtain highly stable and dendrite-free Zn-anode. Stable Zn plating/stripping for over 3000 hours was obtained accompanied with a CE of 99.68%. The SEM images of the Zn-anodes revealed highly porous interconnected dendrite-free Z...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Naveed A, Yang H, Yang J, Nuli Y, Wang J Tags: Angew Chem Int Ed Engl Source Type: research

Optical spectroscopy of the Au4+ cluster: Resolved vibronic structure indicates an unexpected isomer*.
This study demonstrates that an analysis of low-resolution electronic spectra by calculations of vertical transitions alone is not sufficient for a reliable isomer assignment of such metal clusters. PMID: 30600582 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Förstel M, Schewe W, Dopfer O Tags: Angew Chem Int Ed Engl Source Type: research

Hidden conformations in Aspergillus niger Monoamine Oxidase key for catalytic efficiency.
una S Abstract Enzymes exist as an ensemble of conformational states, whose populations can be shifted by substrate binding, allosteric interactions, but also by introducing mutations to their sequence. Tuning the populations of the enzyme conformational states through mutation enables evolution towards novel activity. In this paper, we use Markov state models to unveil hidden conformational states of Monoamine Oxidase from Aspergillus niger (MAO-N). These hidden conformations, not previously observed by means of any other technique, play a crucial role in substrate binding and enzyme activity. Our work reveals ho...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Curado-Carballada C, Feixas F, Iglesias-Fernández J, Osuna S Tags: Angew Chem Int Ed Engl Source Type: research

Three-in-one oxygen vacancy: whole visible-spectrum absorption, efficient charge separation and surface site activation for robust CO2 photoreduction.
Abstract Exploitation of efficient catalysts to realize solar-driven conversion of inert CO2 into useful fuels confronts big challenges owing to the poor photoabsorption, sluggish charge separation and inefficient surface reactive sites of photocatalysts. Herein, we report a facile and controllable in situ reduction strategy to create surface oxygen vacancies (OVs) on Aurivillius-phase Sr2Bi2Nb2TiO12 to tackle all aforementioned issues. Sr2Bi2Nb2TiO12 nanosheets are for the first time prepared by a mineralizer-assisted soft-chemical method, and the introduction of OVs on the surface of Sr2Bi2Nb2TiO12 not only exte...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Yu H, Li J, Zhang Y, Yang S, Han K, Dong F, Ma T, Huang H Tags: Angew Chem Int Ed Engl Source Type: research

Z-Scheme 2D/2D Heterojunction of Black Phosphorus/Monolayer Bi2WO6 Nanosheets with Enhanced Photocatalytic Activities.
Abstract Black phosphorus (BP), a star-shaped two-dimensional material, has attracted considerable attention owing to its unique chemical and physical properties. BP shows great potential in photocatalysis area because of its excellent optical properties; however, its applications in this field have been limited to date. Herein, we design and fabricate a Z-Scheme heterojunction of 2D/2D BP/monolayer Bi2WO6 (MBWO) by a simple and effective method. The BP/MBWO heterojunction exhibits enhanced photocatalytic performance in photocatalytic water splitting to produce H2 and NO removal to purify air; the highest H2 evolu...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Hu J, Chen D, Mo Z, Li N, Xu Q, Li H, He J, Xu H, Lu JM Tags: Angew Chem Int Ed Engl Source Type: research

Sulfilimines as Versatile Gold Nitrene Transfer Reagents: Facile Access to Aza-Heterocyclic Diversity.
Abstract We herein report the unprecedented synthesis of diverse biologically important aza-heterocycles by employing sulfilimines as nitrene transfer reagents, this class of sulfur-based aza-ylides has not been successfully used for gold nitrene transfer before. This work contains an efficient generation of α-imino gold carbenes via N-S cleavage of sulfilimines. These gold carbenes undergo C-H insertion, cyclopropanation and nucleophilic attack to form indoles (44 examples), 3-azabicyclo[3.1.0]hexan-2-imines (24 examples) and imidazoles (3 examples). This work represents the unique gold-catalyzed reaction b...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Tian X, Song L, Rudolph M, Rominger F, Oeser T, Hashmi ASK Tags: Angew Chem Int Ed Engl Source Type: research

Isolated Zn-Co Atomic Pair for Highly Active and Durable Oxygen Reduction.
Abstract N-coordinated nonprecious dual metal catalysts have demonstrated superior catalytic activity by offering more concentrated active sites. However a rational design of such system remains conceptually challenging which requires in-depth research both experimentally and theoretically. Herein, we develop a competitive complexation strategy to construct a novel electrocatalyst with Zn-Co atomic pairs coordinated on N doped carbon support (Zn/CoN-C). Such architecture offers enhanced binding ability of O2, significantly elongates the O-O length (from 1.23 Å to 1.42 Å), and thus facilitates the cleav...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Lu Z, Wang B, Hu Y, Liu W, Zhao Y, Yang R, Li Z, Luo J, Chi B, Jiang Z, Li M, Mu S, Liao S, Zhang J, Sun X Tags: Angew Chem Int Ed Engl Source Type: research

Spectroscopic and Computational Evidence of Intramolecular Au(I) ···H+-N Hydrogen Bonding.
Spectroscopic and Computational Evidence of Intramolecular Au(I)···H+-N Hydrogen Bonding. Angew Chem Int Ed Engl. 2019 Jan 02;: Authors: Rulíšek L, Straka M, Andris E, Vícha J, Růžička A, Roithová J Abstract Despite substantial evidence of short Au···H-X contacts derived from a number of X-ray structures of Au(I) compounds, the nature of Au(I)···H bonding has not been clearly understood. Herein, we present the first spectroscopic evidence for intramolecular Au(I)···H+-N hydrogen bond in a...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Rulíšek L, Straka M, Andris E, Vícha J, Růžička A, Roithová J Tags: Angew Chem Int Ed Engl Source Type: research

Stereospecific Synthesis of α-Hydroxy-Cyclopropylboronates from Allylic Epoxides.
Stereospecific Synthesis of α-Hydroxy-Cyclopropylboronates from Allylic Epoxides. Angew Chem Int Ed Engl. 2019 Jan 02;: Authors: Tortosa M, Amenós L, Trulli L, Nóvoa L, Parra A Abstract Herein, we report a catalytic and stereospecific method for the preparation of enantioenriched α-hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be ...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Tortosa M, Amenós L, Trulli L, Nóvoa L, Parra A Tags: Angew Chem Int Ed Engl Source Type: research

Enantioselective Synthesis of 3,3'-Diaryl-SPINOLS by Rh-Catalyzed Asymmetric Arylation-BF3-Promoted Spirocyclization Reactions.
Abstract Enantioselective synthesis of a series of C2-symmetric 3,3'-diarylated 1,1'-spirobiindane-7,7'-diols (3,3'-Diaryl-SPINOLS) was developed via a sequential Rh-catalyzed two-fold asymmetric conjugate arylation-BF3-promoted diastereoselective spirocyclization process (>20:1 dr and>99% ee for all the examples). Some phosphoramidite ligands were prepared from the 3,3'-Ph-SPINOL and applied to several catalytic asymmetric reactions, where the 3,3'-diarylated ligands showed higher enantioselectivities than the privileged non-substituted ones. PMID: 30600869 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Yin L, Xing J, Wang Y, Shen Y, Lu T, Hayashi T, Dou X Tags: Angew Chem Int Ed Engl Source Type: research

A Hybrid Platform Based on a Bispecific Peptide-Antibody Complex for Targeted Cancer Therapy.
Abstract Peptide-based therapeutics have suffered from a short plasma half-life. On the other hand, antibodies suffer from poor penetration in solid tumors owing to their large size. Here, we present a new molecular form-a hybrid complex between a hapten-labeled bispecific peptide and an anti-hapten antibody, designated HyPEP-body-that may be able to overcome the aforementioned limitation. A bispecific peptide containing a cotinine tag was synthesized by linking a peptide specific to fibronectin extra domain B (EDB) and a peptide able to bind and inhibit vascular endothelial growth factor (VEGF), yielding cot-biPE...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Yu B, Hwang D, Jeon H, Kim H, Lee Y, Keum H, Kim J, Lee DY, Kim Y, Chung J, Jon S Tags: Angew Chem Int Ed Engl Source Type: research

Nanostars on Nanopipettes: A Raman Probe for Quantifying Oxygen Levels in Hypoxia in Single Cells and Tumors.
Abstract Multiple sharp-edged gold nanostars were efficiently assembled on nanopipett tips by 3-aminopropyltrimethoxysilane (APTES) via an electrostatic interaction for a potent intracellular hypoxia-sensing Raman probe. Colloidal stability and surface immobiization was checked using scanning electron microscopy, light scattering and zeta potential measurements. Site-specific intracellular hypoxia levels can be estimated in vitro and in vivo using Raman lancets (RL). Distinct Raman spectral changes for the nitro-(NO2) functional group of the redox maker 4-nitrothiophenol (4NTP) can be quantified according to the i...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Lee SY Tags: Angew Chem Int Ed Engl Source Type: research

Enantioselective Aminohydroxylation of Styrenyl Olefins Catalyzed by an Engineered Hemoprotein.
FH Abstract Chiral 1,2-amino alcohols are widely represented in biologically active compounds from neurotransmitters to antivirals. While many synthetic methods have been developed for accessing amino alcohols, the direct aminohydroxylation of alkenes to unprotected, enantioenriched amino alcohols remains a challenge. Using directed evolution, we have engineered a hemoprotein biocatalyst based on a thermostable cytochrome c that directly transforms alkenes to amino alcohols with high enantioselectivity (up to 2500 TTN and 90% ee) under anaerobic conditions with O-pivaloylhydroxylamine as an aminating reagent. The...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Cho I, Prier CK, Jia ZJ, Zhang RK, Görbe T, Arnold FH Tags: Angew Chem Int Ed Engl Source Type: research

Anchoring Artificial Solid Electrolyte Interphase Layer on 3D Current Collector for High-Performance Lithium Anode.
Abstract The application of Li anode is hindered by the dendrite growth and side reactions between Li and electrolyte, despite its high capacity and low potential. Herein, we demonstrate a simple approach for this challenge. In our strategy, the garnet-type Li6.4La3Zr1.4Ta0.6O12 (LLZTO) based artificial solid electrolyte interphase (SEI) is anchored on Cu foam by sintering the Cu foam coated with LLZTO particles. The heat-treatment leads to the interdiffusion of Cu and Ta2O5 at Cu/LLZTO interface, through which LLZTO layer is fixed on Cu foam. 3D structure lowers the current density, and meanwhile the SEI reduces ...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Wang Y, Li P, Dong X, Li C, Liu J, Liu Y, Feng W, Wang C, Xia Y Tags: Angew Chem Int Ed Engl Source Type: research

Catalysis by Visible Light Photoexcited Palladium Complexes.
Abstract A new area of visible light-induced Pd-catalysis has been emerging into the field. In contrast to the classical ground-state Pd-catalyzed reactions mostly proceeding via two-electron redox manifold, the mechanisms for these new Pd-photoexcited methods usually operate via a single electron transfer process, thus leading to putative Pd-radical hybrid species, which exhibit both radical and classical Pd-type reactivity. This minireview highlights the recent progress in this rapidly growing area. PMID: 30600875 [PubMed - as supplied by publisher] (Source: Angewandte Chemie)
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Gevorgyan V, Chuentragool P, Kurandina D Tags: Angew Chem Int Ed Engl Source Type: research

Chemical Regulation of DNA i-Motifs for Nanobiotechnology and Therapeutics.
Abstract DNA sequences rich in cytosine have the propensity to fold into four-stranded intercalated DNA structures called i-motifs under acidic pH. A string of recent studies provided significant breakthroughs that demonstrate how chemists can manipulate these structures for nanobiotechnology and therapeutics. The first section of this minireview discusses the development of advanced functional nanostructures by synthetic conjugation of i-motifs with organic scaffolds and metal nanoparticles and their role in therapeutics. The second section highlights the therapeutic targeting of i-motifs with chemical scaffolds ...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Dash J, Debnath M, Fatma K Tags: Angew Chem Int Ed Engl Source Type: research

One-Dimensional Fe2P Acted as Fenton Agent Response to NIR II Light and Ultrasound for Deep Tumor Synergetic Theranostic.
Abstract Stringent reaction condition of effective Fenton reaction (the pH range of 3-4) hinders its further application in cancer therapy. Therefore, how to improve the efficiency of Fenton reaction in tumor site has been the main obstacle of chemodynamic therapy (CDT). Herein, we report biocompatible one-dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)- and photothermal (PT)-enhanced Fenton properties and excellent photothermal conversion efficiency (56.6%) in the NIR II window, showing remarkably synergistic therapeutic properties. Additionally, FP NRs can be used as excellent photoacou...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Song S, Liu Y, Zhen W, Wang Y, Liu J, Jin L, Zhang T, Zhang S, Zhao Y, Yang Y, Zhang H, Li C, Zhu J Tags: Angew Chem Int Ed Engl Source Type: research

The bacterial [Fe]-hydrogenase paralog uses tetrahydrofolate derivatives as substrates.
Abstract [Fe]-hydrogenase (Hmd) catalyzes the reversible hydrogenation of methenyl-tetrahydromethanopterin (methenyl-H4MPT+) with H2. H4MPT is a C1-carrier of methanogenic archaea. One bacterial genus, Desulfurobacterium, contains putative genes for the Hmd paralog (HmdII) and the HcgA-G proteins. The latter are involved in biosynthesis of the prosthetic group of Hmd, the iron-guanylylpyridinol (FeGP) cofactor. This finding is intriguing because Hmd and HmdII strictly use H4MPT derivatives that are absent in most bacteria. We identified the presence of the FeGP cofactor in D. thermolithotrophum. The bacterial HmdI...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Watanabe T, Wagner T, Huang G, Kahnt J, Ataka K, Ermler U, Shima S Tags: Angew Chem Int Ed Engl Source Type: research

Freezing Induced Turn-on Modality for Real-time Imaging in Cryosurgery.
Abstract Cryosurgery has attracted great attention for the treatment of tumors due to its obvious advantages. However, it still remains a challenge to determine the volume of frozen tissues in real-time, which greatly lowers the therapeutic efficacy of cryosurgery and hinders its broad application for the treatment of cancers. Herein, we report a freezing induced turn-on strategy for selective real-time imaging of frozen cancer cells. As a type of aggregation induced emission (AIE) fluorogen, TABD-Py molecules interact specifically with ice crystals and form aggregates at the ice/water interface. Consequently, bri...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: He Z, Liu P, Zhang S, Yan J, Wang M, Cai Z, Wang J, Dong Y Tags: Angew Chem Int Ed Engl Source Type: research

Palladium/Norbornene-Catalyzed Indenone Synthesis from Simple Aryl Iodides: Concise Syntheses of Pauciflorol F and Acredinone A.
Abstract To show the synthetic utility of palladium/norbornene (Pd/NBE) cooperative catalysis, here we report concise syntheses of indenone-based natural products, pauciflorol F and acredinone A, which are enabled by direct annulation between aryl iodides and unsaturated carboxylic acid anhydrides. Compared to the previous indenone-preparation approaches, this method allows simple aryl iodides to be used as substrates with complete control of the regioselectivity. The total synthesis of acredinone A features two different Pd/NBE-catalyzed ortho acylation reactions for constructing penta-substituted arene cores, in...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Liu F, Dong Z, Wang J, Dong G Tags: Angew Chem Int Ed Engl Source Type: research

An Insight into 6 π Electrocyclic Reactions of 1,8-Dioxatetraene.
An Insight into 6π Electrocyclic Reactions of 1,8-Dioxatetraene. Angew Chem Int Ed Engl. 2019 Jan 02;: Authors: Si X, Jia Y, Luan X, Yang L, Pei Y, Zhou W Abstract A variety of benzofuranone-based spiroisochromenes were originally designed and synthesized for an insight into the oxa-6π electrocyclic reaction of cis, cis-1,8-dioxatetraene for the first time. The stability of the 1,8-dioxatetraene is governed by its steric congestion and can be fine-tuned through backbone structure modification, leading to the reactivity differences in 6π electrocyclic reaction and to the emergence of photochro...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Si X, Jia Y, Luan X, Yang L, Pei Y, Zhou W Tags: Angew Chem Int Ed Engl Source Type: research

Chemical and topographical single-cell imaging by near-field desorption mass spectrometry.
Abstract Simultaneous acquiring chemical and topographical information within a single cell at nanoscale resolutions is vital to cellular biology, yet it remains a great challenge for current techniques due to limited lateral resolutions and detection sensitivities. Here we report the development of near-field desorption mass spectrometry for correlated chemical and topographical imaging, thereby bridging the gap between laser-based MS methods and multimodal single-cell imaging. Using this integrated platform, imaging resolution of 250 nm and 3D topographically reconstructed chemical single-cell imaging were achie...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Hang W, Yin Z, Cheng X, Liu R, Li X, Hang L, Xu J, Yan X, Li J, Tian Z Tags: Angew Chem Int Ed Engl Source Type: research

A Guiding Principle for Toughening Cross-Linked Polymers: Synthesis and Application of Mobility-Controlling Rotaxane Cross-Linkers.
Abstract Three-component mobility-controlling vinylic rotaxane cross-linkers with two radically polymerizable vinyl groups (RC_Rs) were synthesized to prove that the mobility of the components of the RC_Rs plays a crucial role in determining the properties of rotaxane-cross-linked polymers (RCPs). RC_Rs (R = H, Me, or Et) were obtained from the living ring-opening polymerization of six-membered cyclic carbonates with two substituents R at the 5 position using pseudorotaxane initiators with a terminal OH group on the axle. A mixture of n-butyl acrylate and 0.5 mol% RC_R was exposed to UV irradiation in the presence...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Sawada J, Aoki D, Otsuka H, Takata T Tags: Angew Chem Int Ed Engl Source Type: research

Direct Carbohydroxylation of Arylalkenes with Allylic Alcohols through Cooperative Catalysis of Copper, Silver, and Br ønsted Acid.
Direct Carbohydroxylation of Arylalkenes with Allylic Alcohols through Cooperative Catalysis of Copper, Silver, and Brønsted Acid. Angew Chem Int Ed Engl. 2019 Jan 02;: Authors: Ahmed W, Zhang S, Yu X, Feng X, Yamamoto Y, Bao M Abstract Cooperative catalysis of copper, silver, and Brønsted acid is presented as a new strategy for olefin functionalization. The catalytic direct carbohydroxylation of arylalkenes with allylic alcohols provided a straightforward and efficient approach for preparing 4,5-unsaturated alcohols. Synthetically useful functional groups, such as Cl, Br, carbonyl, and ...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Ahmed W, Zhang S, Yu X, Feng X, Yamamoto Y, Bao M Tags: Angew Chem Int Ed Engl Source Type: research

Influence of hydronium ions in zeolites on sorption.
her J Abstract In presence of sufficient concentrations of water, stable, hydrated, hydronium ions are formed in the pores and at the surface of solid acids such as zeolites. For a medium pore zeolite, such as zeolite MFI, the hydrated hydronium ions consist of eight water molecules and have an effective volume of 0.24 nm³. In their presence, larger organic molecules can only adsorb in the portions of the pore that are not occupied by hydronium ions. In consequence, the available pore volume decreases proportionally to the concentration of the hydronium ions. The higher charge density (the increasing ionic st...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Eckstein S, Hintermeier PH, Zhao R, Baráth E, Shi H, Liu Y, Lercher J Tags: Angew Chem Int Ed Engl Source Type: research

Activation of MoS2 Basal Planes for Hydrogen Evolution through Zinc.
Abstract Molybdenum disulfide (MoS2) has been widely studied as a potential earth-abundant electrocatalyst for the hydrogen-evolution reaction (HER). Defects engineering and hetero-elemental doping are effective methods to enhance the catalytic activity for HER, so exploring an efficient route to achieve in-plane vacancy engineering and elemental doping of MoS2 simultaneously is necessary. Herein, Zinc as a low-cost and moderate active metal has been used to realize the strategy by generating Sulphur (S) vacancies and zinc doping on MoS2 in one-step. Density functional theory calculations reveal the doping zinc at...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Wu W, Niu C, Wei C, Jia Y, Li C, Xu Q Tags: Angew Chem Int Ed Engl Source Type: research

Total Synthesis and Anticancer Activity of (+)-Hypercalin C and Congeners.
We report the first total synthesis of (+)-hypercalin C employing a convergent strategy that enabled dissection of the essential structural features required for the observed anticancer activity. A strategic disconnection involving an unusual Csp3-Csp2 Suzuki-Miyaura coupling with an α-bromo enolether also revealed an unexpected C-H activation. Our strategy targeted designed analogs along the synthetic route to address particular biological questions. Our results support the hypothesis that hypercalin C may act as a proton shuttle with the dearomatized acylphloroglucinol moiety being essential for this activity. ...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Romo D, Tao Y, Reisenauer K, Taube JH Tags: Angew Chem Int Ed Engl Source Type: research

Aromatic Azide Transformation on the Ag(111) Surface Studied by Scanning Probe Microscopy.
á IG, Jelínek P Abstract Chemical transformation of 9-azidophenanthrene on the Ag(111) surface was studied by nc-AFM in UHV. High-resolution imaging supported by first-principle calculations revealed the structure of the final products that originated from a common and elusive 9-phenanthryl nitrenoid intermediate chemisorbed on the Ag(111) surface. A formal "nitrene" insertion into the C-H bond along with its dimerisation and hydrogenation were identified as main reaction channels. Thus, the ability of aryl azides to form covalent σ- and π-bonds between their transformation product...
Source: Angewandte Chemie - January 2, 2019 Category: Chemistry Authors: Stary I, Hellerstedt J, Cahlík A, Stetsovych O, Švec M, Shimizu TK, Mutombo P, Klívar J, Stará IG, Jelínek P Tags: Angew Chem Int Ed Engl Source Type: research