A Novel Modified Cross-Coupling of Phenols and Amines Using Dichloroimidazolidinedione (DCID)
Synlett DOI: 10.1055/s-0040-1707224 Phenols are considered as an ideal alternative to aryl halides as coupling partners in cross-coupling reactions. In the present work a copper-catalyzed cross-coupling of phenols with various aromatic and aliphatic amines for the synthesis of secondary aryl amines using dichloroimidazolidinedione (DCID) as a new and efficient activating agent has been developed. Substituted phenols were compatible with the standard reaction conditions. The two proposed mechanisms, which are based on the oxidation addition of copper with Ar-OMCID (MCID: Monochloroimidazolidinedione), are also discussed. [....
Source: Synlett - August 3, 2020 Category: Chemistry Authors: Madankar, Kamelia Mokhtari, Javad Mirjafary, Zohreh Tags: letter Source Type: research

A Stable Precursor for Bioorthogonally Removable 3-Isocyanopropyloxycarbonyl (ICPrc) Protecting Groups
Synlett DOI: 10.1055/s-0040-1707220 Studies have established 3-isocyanopropyloxycarbonyl (ICPrc) moieties as bioorthogonally removable protecting groups. However, reagents to prepare ICPrc-protected amines are unstable, which critically limits the practical implementation of this chemistry. Here we report 3-isocyanopropyl (pentafluorophenyl) carbonates as bench-stable precursors for the synthesis of ICPrc-protected primary and secondary amines. The utility of the chemistry for bioconjugation applications is demonstrated by reversibly masking a lysine residue on a bioactive peptide. [...] © Georg Thieme Verlag Stu...
Source: Synlett - July 31, 2020 Category: Chemistry Authors: Tu, Julian Xu, Minghao Franzini, Raphael M. Tags: letter Source Type: research

Concise Total Synthesis of (+)-Atlanticone C
Synlett DOI: 10.1055/s-0040-1707215 The first enantioselective total synthesis of (+)-atlanticone C is described. The complex tricyclic protoilludane core was rapidly assembled by a photochemical reaction cascade starting from an easily accessible indanone precursor (3 steps). Optimization of an enantioselective Corey–Bakshi–Shibata reduction permitted a catalytic chiral reso­lution of the racemic photoproduct (45% over two steps; up to 98% ee). The enantiomerically enriched photoproduct was efficiently transformed into the (+)-enantiomer of atlanticone C (10 steps; 18% yield), and the absolute co...
Source: Synlett - July 31, 2020 Category: Chemistry Authors: Proessdorf, Johanna Zech, Andreas Jandl, Christian Bach, Thorsten Tags: letter Source Type: research

C(sp3) –H Bond Functionalization of Alcohols, Ketones, Nitriles, Ethers and Amides using tert-Butyl Hydroperoxide as a Radical Initiator
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 31, 2020 Category: Chemistry Authors: Wang, Nai-Xing Zhang, Lei-Yang Wu, Yue-Hua Xing, Yalan Tags: account Source Type: research

Total Synthesis of Ascospiroketal B
Synlett DOI: 10.1055/s-0040-1706405 An enantioselective total synthesis of the marine tricyclic polyketide ascospiroketal B, previously isolated from the marine-derived fungus Ascochyta salicorniae, was accomplished in 21 steps by using an improved route. The intriguing 5,5-spiroketal-cis-fused-γ-lactone core was constructed through rearrangement of an epoxide, in conjunction with an acid-mediated spiroketalization. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 30, 2020 Category: Chemistry Authors: Hara, Yoshiyori Kamaike, Kazuo Ota, Koichiro Miyaoka, Hiroaki Tags: letter Source Type: research

Palladium/Sensory Component-Catalyzed Homocoupling Reactions of Aryl Halides
Synlett DOI: 10.1055/s-0040-1707214 A novel and efficient catalyst system was developed for homocoupling reactions of aryl halides. The catalyst system consists of Pd(OAc)2 and the peppery sensory component of tobacco leaves. This is the first time that a sensory component has been used in an organic reaction. Experiments using the catalyst system showed that the reactions proceeded smoothly under air in the absence of both an additional ligand and a reductant. Furthermore, the catalyst system can be applied to the coupling reactions of hetaryl iodides. Many functional groups (including a hydroxy group) are tolerated. [......
Source: Synlett - July 29, 2020 Category: Chemistry Authors: Bao, Fengyu Liu, Zhikai Bai, Haixin Zhang, Haiyan Liu, Pengfei Zhang, Qidong Chai, Guobi Tags: letter Source Type: research

Taming Nitrene Reactivity with Silver Catalysts
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 29, 2020 Category: Chemistry Authors: Vine , Logan E. Zerull, Emily E. Schomaker, Jennifer M. Tags: account Source Type: research

Synform issue 2020/08
Synlett 2020; 31: A108-A123 DOI: 10.1055/s-0039-1691195 © Georg Thieme Verlag KG Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - July 28, 2020 Category: Chemistry Authors: Zanda, Matteo Tags: Synform Source Type: research

Linked PDF of Table of Contents
Synlett 2020; 31: V- DOI: 10.1055/s-0040-1706410 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - July 28, 2020 Category: Chemistry Tags: table of contents Source Type: research

Nickel-Catalyzed Asymmetric Cross-Electrophile Coupling Reactions
Synlett DOI: 10.1055/s-0040-1707216 The merger of cross-electrophile coupling and asymmetric catalysis provides a novel approach to the preparation of optically active compounds. This method is often endowed with high step economy, mild conditions, and excellent tolerance of functional groups. Recent advances in the research field of nickel-catalyzed asymmetric cross-electrophile coupling reactions are highlighted in this concise Synpacts article.1 Introduction2 Asymmetric Cross-Electrophile Coupling Reactions between Organohalides3 Asymmetric Electrophilic Ring-Opening Reactions4 Asymmetric Electrophilic Difunctionali...
Source: Synlett - July 27, 2020 Category: Chemistry Authors: Jin, Youxiang Wang, Chuan Tags: synpacts Source Type: research

Total Synthesis of Stemoamide, 9a-epi-Stemoamide, and 9a,10-epi-Stemoamide: Divergent Stereochemistry of the Final Methylation Steps
Synlett DOI: 10.1055/s-0040-1707201 Total syntheses of stemoamide, 9a-epi-stemoamide, and 9a,10-epi-stemoamide by a convergent A + B ring-forming strategy is reported. The synthesis required a diastereoselective late-stage methylation of the ABC stemoamide core that successfully enabled access to three of the four possible diastereomeric structures. For the natural stemoamide series, the diastereoselectivity can be rationalized both by kinetic and thermodynamic arguments, whereas for the natural 9a-epi-stemoamide series, the kinetic selectivity is explained by the prepyramidalization of the relevant enolate. [...] ©&n...
Source: Synlett - July 27, 2020 Category: Chemistry Authors: Siitonen, Juha H. Cs ókás, Dániel P ápai, Imre Pihko, Petri M. Tags: letter Source Type: research

Facile Synthesis of β-Bromostyrenes by Direct Bromination of Styrenes with N-Bromosuccinimide and Sodium Persulfate
Synlett DOI: 10.1055/s-0040-1707199 A new, direct, efficient, and transition-metal-free method is reported for the synthesis of β-bromostyrenes from styrenes by using N-bromosuccinimide as the brominating reagent and sodium persulfate (Na2S2O8) as the oxidant. This convenient and concise reaction is practical, operationally simple, and can be adapted for large-scale syntheses. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 27, 2020 Category: Chemistry Authors: Jing, Yi Gao, Yan Zhao, Qianyi Chen, Xuenian Ma, Yan-Na Tags: letter Source Type: research

C −H Arylation of Thiophenes with Aryl Bromides by a Parts-per-Million Loading of a Palladium NNC-Pincer Complex
Synlett DOI: 10.1055/s-0040-1707213 A palladium NNC-pincer complex efficiently catalyzed the direct arylation of thiophene derivatives with extremely low palladium loadings of the order of parts per million. Thus, the reaction of various thiophenes with aryl bromides in the presence of 25–100 mol ppm of chlorido[(2-phenyl-κ-C 2)-9-phenyl-1,10-phenanthroline-κ2-N,N′]palladium(II) NNC-pincer complex, K2CO3, and pivalic acid in N,N-dimethyl­acetamide afforded the corresponding 2- or 5-arylated thiophenes in good to excellent yields. A combination of the present C–H arylation and Hiyam...
Source: Synlett - July 24, 2020 Category: Chemistry Authors: Purta, Anggi Eka Ichii, Shun Tazawa, Aya Uozumi, Yasuhiro Tags: letter Source Type: research

DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives
Synlett DOI: 10.1055/s-0040-1707909 A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondary propargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer–Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy, and excellent yields are among the prominent features of the reaction. Additionally, the photophysical properties and crystal-structure-packing behavior of selected compou...
Source: Synlett - July 24, 2020 Category: Chemistry Authors: De, Rimpa Savarimuthu, Antony Ballav, Tamal Singh, Pijush Nanda, Jayanta Hasija, Avantika Chopra, Deepak Bera, Mrinal K. Tags: letter Source Type: research

Synthesis and Functions of Oligomeric and Multidentate Dipyrrin Derivatives and their Complexes
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 24, 2020 Category: Chemistry Authors: Chiba, Yusuke Nakamura, Takashi Matsuoka, Ryota Nabeshima, Tatsuya Tags: account Source Type: research

An Efficient Palladium-Catalyzed α-Arylation of Acetone Below its Boiling Point
Synlett DOI: 10.1055/s-0040-1706409 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Full text (Source: Synlett)
Source: Synlett - July 23, 2020 Category: Chemistry Authors: Richardson, Jeffery Mutton, Simon P. Martin, Fionna M. Walton, Lesley Ledgard, Andrew J. Tags: errata Source Type: research

Iron-Catalyzed Diastereoselective Synthesis of Disubstituted Morpholines via C –O or C–N Bond Formation
Synlett DOI: 10.1055/s-0040-1707902 The diastereoselective synthesis of 2,6- and 3,5-disubstituted morpholines was achieved from 1,2-amino ethers and 1,2-hydroxy amines substituted by an allylic alcohol using an iron(III) catalyst. The morpholines were obtained either by C–O or C–N bond formation. A plausible mechanism is suggested, involving a thermodynamic equilibrium to explain the formation of the cis diastereoisomer as the major product. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Fu...
Source: Synlett - July 23, 2020 Category: Chemistry Authors: Aubineau, Thomas Dupas, Alexandre Zeng, Tian Cossy, Janine Tags: cluster Source Type: research

Synthesis of Polycyclic Natural Products through Skeletal Rearrangement
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 23, 2020 Category: Chemistry Authors: Yokoshima, Satoshi Tags: account Source Type: research

Building Complexity and Achieving Selectivity through Catalysis – Case Studies from the Pharmaceutical Pipeline
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 23, 2020 Category: Chemistry Authors: Beaver, Matthew G. Caille, Seb Farrell, Robert P. R ötheli, Andreas R. Smith, Austin G. Tedrow, Jason S. Thiel, Oliver R. Tags: account Source Type: research

Asymmetric Reductive Dicarbofunctionalization of Alkenes via Nickel Catalysis
Synlett DOI: 10.1055/s-0040-1707900 Alkenes are an appealing functional group that can be transformed into a variety of structures. Transition-metal catalyzed dicarbofunctionalization of alkenes can efficiently afford products with complex substitution patterns from simple substrates. Under reductive conditions, this transformation can be achieved while avoiding stoichiometric organometallic reagents. Asymmetric difunctionalization of alkenes has been underdeveloped, in spite of its potential synthetic utility. Herein, we present a summary of our efforts to control enantioselectivity for alkene diarylation with a nickel ca...
Source: Synlett - July 22, 2020 Category: Chemistry Authors: Anthony, David Diao, Tianning Tags: synpacts Source Type: research

[(bpy)CuSCF3]: A Practical and Efficient Reagent for the Construction of C –SCF3 Bonds
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 22, 2020 Category: Chemistry Authors: Huang, Yangjie Zhang, Mengjia Lin, Qi Weng, Zhiqiang Tags: account Source Type: research

Iron-Catalyzed Aerobic Oxidative Cross-Dehydrogenative C(sp3) –H/X–H (X = C, N, S) Coupling Reactions
Conclusion and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 21, 2020 Category: Chemistry Authors: Hu, Ren-Ming Lai, Yi-Huan Xu, Da-Zhen Tags: synpacts Source Type: research

Synthetic Study on Lactonamycins, Part 2: Stereoselective Access to ABCD-Ring System
Synlett DOI: 10.1055/s-0040-1707198 Toward a stereoselective total synthesis of the lactonamycins, we recently reported an approach to the DEF-ring system. Here we report a model study for constructing the ABCD-ring system, revealing a viable approach through (1) construction of the C-ring by asymmetric benzoin cyclization, (2) introduction of an angular hydroxy group through oxidation of an isoxazolium salt, and (3) construction of the AB rings through a ring-opening/closing sequence. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abs...
Source: Synlett - July 21, 2020 Category: Chemistry Authors: Takikawa, Hiroshi Murata, Kazuki Sato, Shogo Kawada, Takuma Nakakohara, Hiroshi Ohmori, Ken Suzuki, Keisuke Tags: letter Source Type: research

Silver-Catalyzed Decarboxylative Radical Addition/Cyclization of Oxamic Acids with Alkenes towards Quinolin-2-ones
Synlett DOI: 10.1055/s-0040-1707891 An efficient silver-catalyzed tandem decarboxylative radical addition/cyclization of oxamic acids with alkenes has been developed. This method provides a novel and straightforward protocol toward a variety of 4-aryl-3,4-dihydroquinolin-2(1H)-ones, 4-(α-carbonyl)-3,4-dihydroquinolin-2(1H)-ones, and quinolin-2(1H)-ones in aqueous solution. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 21, 2020 Category: Chemistry Authors: Jin, Chengan He, Jing-Yao Bai, Qi-Fan Feng, Gaofeng Tags: letter Source Type: research

Divergent Total Syntheses of Six Ganoderma Meroterpenoids: A Bioinspired Two-Phase Strategy
Synlett DOI: 10.1055/s-0040-1707898 We briefly highlight our recent work on the total synthesis of six Ganoderma phenolic meroterpenoids: ganocins A–C, ganocochlearins A–D, and cochlearol T. Critical to this success was a bioinspired two-phase strategy that featured an early-stage rapid construction of a common planar tricyclic intermediate and late-stage highly selective transformations of this intermediate into various Ganoderma meroterpenoids. Key steps of the synthesis include a biomimetic ortho-quinone methide intramolecular hetero-Diels–Alder reaction, a Stahl-type oxidative aromatization, a nucleop...
Source: Synlett - July 20, 2020 Category: Chemistry Authors: Zhang, Fen Zhao, Yu-Ming Tags: synpacts Source Type: research

A Novel Approach to Substituted α-Carbamoyl Phosphonates: Useful Reagents for the Horner–Wadsworth–Emmons Olefination
Synlett DOI: 10.1055/s-0040-1707200 α-Carbamoyl phosphonates are useful reagents for the Horner–Wadsworth–Emmons olefination of aldehydes en route to medicinally relevant polysubstituted acrylamides. A new synthetic approach to these reagents has been developed. The methodology relies on the microwave-promoted Wolff rearrangement of α-acyl-α-diazophosphonates with trapping of the ketene intermediate in situ with various amines. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  ...
Source: Synlett - July 20, 2020 Category: Chemistry Authors: Inyutina, Anna Chupakhin, Evgeny Dar ’in, Dmitry Krasavin, Mikhail Tags: letter Source Type: research

From Enantioselective to Regiodivergent Epoxide Opening and Radical Arylation – Useful or Just Interesting?
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 20, 2020 Category: Chemistry Authors: Gans äuer, Andreas Tags: account Source Type: research

Decarboxylative Bromination of Heteroarenes: Initial Mechanistic Insights
Synlett DOI: 10.1055/s-0040-1707901 After an initial report from our laboratory describing metal-free decarboxylative halogenation of various azaheteroarenes, we set out to investigate the possible mechanism by which this chemistry occurs. Evidence from this mechanistic investigation suggests that this chemistry occurs via a radical pathway, with 1H NMR studies suggesting that the acidic substrates activate NBS. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 17, 2020 Category: Chemistry Authors: Patel, Pritesh R. Henderson, Scott H. Roe, Mark S. Honey, Mark A. Tags: letter Source Type: research

Quinolin-8-yl Formate: A New Option for Small-Scale Carbonylation Reactions in Microwave Reactors
Synlett DOI: 10.1055/s-0040-1707187 A convenient procedure for conducting small-scale carbonylations of aryl or benzyl halides in a microwave reactor by using quinolin-8-yl formate is described. The resulting 8-acyloxyquinolines were shown to be more reactive than phenyl esters in acyl-transfer reactions, and their utility for the production of esters and amides was demonstrated. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 17, 2020 Category: Chemistry Authors: Maddocks, Christopher J. Aathimanikandan, Sivakumar V. Richardson, Jeffery Ruble, J. Craig Tags: letter Source Type: research

Ni-Catalyzed Intramolecular Reductive 1,2-Dicarbofunctionalization of Alkene: Facile Access to Podophyllum Lignans Core
Synlett DOI: 10.1055/s-0040-1707188 The facile access to the tetracyclic skeleton of podophyllotoxin, a medicinally important lignan natural product, was efficiently achieved via a unique intramolecular alkylarylation of the tethered alkene in a dihalide under mild conditions using reductive nickel catalysis. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 17, 2020 Category: Chemistry Authors: Xiao, Jian Wang, Ya-Wen Qiu, Zhong-Ping Peng, Yu Tags: cluster Source Type: research

Iodine-Promoted Synthesis of 4-Aryl-2-(arylsulfonyl)quinolones by Desulfurative C –S Cross-Coupling Reaction of Quinoline-2-thiones with Sodium Sulfinates
Synlett DOI: 10.1055/s-0040-1706868 An iodine-induced sulfonylation of quinoline-2-thiones with sodium arenesulfinates as sulfur sources for the synthesis of 4-aryl-2-(arylsulfonyl)quinoline derivatives is described. The 4-aryl-2-(arylsulfonyl)quinoline derivatives can be obtained in a moderate to good yields. This C–S bond cleavage and C–S cross-coupling proceeds in the absence of a metal under inexpensive and nontoxic conditions and it displays a broad substrate scope. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstra...
Source: Synlett - July 16, 2020 Category: Chemistry Authors: Yang, Guo-Chao Wang, Xi-Chun Quan, Zheng-Jun Tags: letter Source Type: research

Cascade Access to Carboline Carboxylates from Indolyl Ketoximes and Acrylates via Palladium-Catalyzed C –H Bond Alkenylation/Annulation
Synlett DOI: 10.1055/s-0040-1707192 An efficient palladium-catalyzed C–H bond alkenylation/annulation strategy to access carboline carboxylates from indolyl ketoximes and acrylates through C–C/C–N bond formation is reported. Indolyl ketoximes not only direct ortho-olefination with acrylates, but also undergo an intramolecular N–O bond cleavage/traceless annulation to construct carboline carboxylates straightforwardly in this concise method. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |&nbs...
Source: Synlett - July 15, 2020 Category: Chemistry Authors: Fu, Xiao-Pan Chen, Lu Wu, Gao-Rong Liu, Hong-Wei Xia, Cheng-Cai Ji, Ya-Fei Tags: letter Source Type: research

Synergistic Catalysis for Stereodivergent Synthesis of trans- and cis-Skipped Dienes
Synlett DOI: 10.1055/s-0040-1707190 Catalytic, stereoselective synthesis of skipped dienes is an important topic in organic synthesis. Summarized here are the transition-metal-catalyzed stereoselective approaches and a new, photoinduced stereodivergent strategy reported by our group recently. Our strategy utilizes a synergistic photoredox/nickel protocol to enable the cross-electrophile coupling of allylic carbonates and vinyl triflates to construct 1,4-dienes, the stereoselectivity of which was tuned by the triplet energy (E T) photocatalysts employed, offering a convenient and stereodivergent solution to (E)- and (Z)-...
Source: Synlett - July 14, 2020 Category: Chemistry Authors: Wang, Fang Zhu, Shenqqing Chu, Lingling Tags: synpacts Source Type: research

Electronically Governed ROMP: Expanding Sequence Control for Donor –Acceptor Conjugated Polymers
Conclusions [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 14, 2020 Category: Chemistry Authors: Koehler, Stephen J. Hu, Jinzhen Elacqua, Elizabeth Tags: synpacts Source Type: research

Selective 1,4-Addition of Organolithiums to Maleate Monoesters with Application for a Short Efficient Route to Azaindanones
Synlett DOI: 10.1055/s-0040-1707178 The ability of maleate half-ester salts to serve as electrophilic partners in 1,4-conjugate addition reactions with control of regioselectivity has previously been explored in only a limited context with soft nucleophiles. We have demonstrated that benzylic anions of picolines, as well as enolates of ketones, esters, and nitriles, react with lithium 4-(tert-butoxy)-4-oxobutenoate in a completely regioselective manner. This new method was applied to an expedient two-step process for preparing a key azaindanone intermediate for the clinical-candidate drug MK-8666. [...] © Georg T...
Source: Synlett - July 14, 2020 Category: Chemistry Authors: Liu, Zhuqing Hyde, Alan M. Klapars, Artis Chung, John Y. L. Lam, Yu-hong Yasuda, Nobuyoshi Tags: cluster Source Type: research

Dearomatization of a 3-Hydroxypyridine Through an Unexpected Oxidative Deformylation Process: An Entry to Azacyclohexadienones
Synlett DOI: 10.1055/s-0040-1706870 Phenols are well-known precursors of cyclohexadienones, which have widespread applications in organic synthesis. In contrast, their hydroxypyridine counterparts have not been explored yet. An unprecedented oxidative dearomatization of a 3-hydroxypyridine involving an unexpected deformylation step is reported. The chemical reactivity of the resulting unreported azacyclohexadiene-type compound was also explored. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 13, 2020 Category: Chemistry Authors: Mabrouki, Afef Le Nahenec-Martel, Patricia Kriaa, Abdelkader Hedhli, Ahmed Renard, Pierre-Yves Sabot, Cyrille Tags: letter Source Type: research

Bumpy Roads Lead to Beautiful Places: The Twists and Turns in Developing a New Class of PN-Heterocycles
Conclusions and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 13, 2020 Category: Chemistry Authors: Bard , Jeremy P. Johnson, Darren W. Haley, Michael M. Tags: account Source Type: research

Decarboxylative Umpolung Synthesis of Amines from Carbonyl Compounds
Conclusion [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 12, 2020 Category: Chemistry Authors: Chen, Wen-Wen Zhao, Baoguo Tags: synpacts Source Type: research

Formation of Boron Enolates by Nucleophilic Substitution
Synlett DOI: 10.1055/s-0040-1707181 Enolates have proven to be one of the key building blocks available to the synthetic chemist. Here we summarize a novel strategy for their preparation, involving the addition of α-borylated nucleophiles to esters to yield boron enolates. The enolates prepared by the addition of lithiated geminal bis(boron) compounds to esters can be trapped with two equivalents of halogen and alkyl electrophiles to yield α,α-difunctionalized compounds.1 Introduction2 Ketone Difunctionalization3 Boron Enolates by Coupling4 Towards Sequential Trapping5 Summary and Outlook [...] ©...
Source: Synlett - July 9, 2020 Category: Chemistry Authors: Garratt, George R. A. Pattison, Graham Tags: synpacts Source Type: research

Non-planar Boron Lewis Acids Taking the Next Step: Development of Tunable Lewis Acids, Lewis Superacids and Bifunctional Catalysts
Synlett DOI: 10.1055/s-0040-1707078 Although boron Lewis acids commonly adopt a trigonal planar geometry, a number of compounds in which the trivalent boron atom is located in a pyramidal environment have been described. This review will highlight the recent developments of the chemistry and applications of non-planar boron Lewis acids, including a series of non-planar triarylboranes derived from the triptycene core. A thorough analysis of the properties and of the influence of the pyramidalization of boron Lewis acids on their stereoelectronic properties and reactivities is presented based on recent theoretical and experi...
Source: Synlett - July 9, 2020 Category: Chemistry Authors: Chardon, Aur élien Osi, Arnaud Mahaut, Damien Saida, Ali Ben Berionni, Guillaume Tags: synpacts Source Type: research

An Efficient Palladium-Catalyzed α-Arylation of Acetone Below its Boiling Point
We describe our attempts to overcome both issues in the context of our drug-discovery program. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 9, 2020 Category: Chemistry Authors: Richardson, Jeffery Mutton, Simon P. Martin, Fionna M. Walton, Lesley Ledgard, Andrew J. Tags: letter Source Type: research

An Efficient One-Pot Protocol for Direct Access to Diarylmethyl Thioglycosides with para-Quinone Methides via S-Glycosyl Isothiouronium Salts
Synlett DOI: 10.1055/s-0040-1707189 An efficient one-pot protocol has been developed for the direct preparation of diarylmethyl thioglycosides starting from per-O-acetylated sugars via glycosyl isothiouronium salts. The one-pot reaction conditions involve rapid conversion of the per-O-acetylated sugar with thiourea in the presence of boron trifluoride etherate as catalyst to give the corresponding glycosyl isothiouronium salt, which is subsequently treated with a para-quinone methide in the presence of a base to give the a diarylmethyl thioglycoside in excellent yield. [...] © Georg Thieme Verlag Stuttgart &middo...
Source: Synlett - July 9, 2020 Category: Chemistry Authors: Dubey, Atul Mandal, Pintu Kumar Tags: letter Source Type: research

Peptide Cyclization at High Concentration
Conclusion and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 8, 2020 Category: Chemistry Authors: Wills, Rachel D. Adebomi, Victor T. Raj, Monika Tags: synpacts Source Type: research

2-Aminoquinazolines by Chan –Evans–Lam Coupling of Guanidines with (2-Formylphenyl)boronic Acids
Synlett DOI: 10.1055/s-0040-1707080 A new method is presented for the synthesis of 2-aminoquinazolines, which is based on a Chan–Evans–Lam coupling of (2-formylphenyl)boronic acids with guanidines. Relatively mild conditions involving the use of inexpensive CuI as a catalyst and methanol as a solvent permit the application of the method to a wide range of substrates. Nonsubstituted, N-monosubstituted, and N,N-disubstituted guanidines can be used as reactants to give the corresponding 2-aminoquinazolines in moderate yields from readily available (2-formylphenyl)boronic acids. [...] Georg Thieme Verlag Stuttgart ...
Source: Synlett - July 8, 2020 Category: Chemistry Authors: Solomin, Vitalii V. Seins, Alberts Jirgensons, Aigars Tags: letter Source Type: research

A Two-Step Synthesis of a Novel 7,8-Dihydro-5,8-ethanoindolizine-6,9(5H)-dione
Synlett DOI: 10.1055/s-0040-1707182 A two-step synthesis of the novel 5,8-dimethyl-7,8-dihydro-5,8-ethanoindolizine-6,9(5H)-dione from 2,3-dimethyl-1,4-benzoquinone is described. The key step of the synthesis of this unusual fused tricyclic system is the intramolecular regiospecific aza-Michael addition of a pyrrole to an activated double bond by reaction with tetrabutylammonium fluoride under mechanochemical conditions. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 8, 2020 Category: Chemistry Authors: Gallardo-Alfonzo, Salvador Cort és-Garcia, Carlos Jesus Mej ía-Farfán, Itzel L ópez, Yliana Mojica, Martha Contreras-Celed ón, Claudia Chac ón-García, Luis Tags: cluster Source Type: research

Linked PDF of Table of Contents
Synlett 2020; 31: V- DOI: 10.1055/s-0040-1707903 © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents (Source: Synlett)
Source: Synlett - July 6, 2020 Category: Chemistry Tags: table of contents Source Type: research

Isoprene: A Promising Coupling Partner in C –H Functionalizations
Conclusion and Outlook [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 2, 2020 Category: Chemistry Authors: Zhang, Wei-Song Hu, Yan-Cheng Chen, Qing-An Tags: synpacts Source Type: research

Copper-Catalyzed Methylthiolation of Aryl Iodides and Bromides with Dimethyl Disulfide in Water
Synlett DOI: 10.1055/s-0040-1707131 An efficient route to aryl methyl sulfides through the copper-catalyzed coupling reaction of aryl iodides or bromides with dimethyl disulfide in water is described. Electron-donating and electron-withdrawing functional groups in the substrates were tolerated, and the corresponding products were obtained in moderate to good yields. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 2, 2020 Category: Chemistry Authors: Wang, Ying-yu Wu, Xiang-mei Yang, Ming-hua Tags: letter Source Type: research

Facile Approach to Geminal Heterodihalogenation. One-Pot Synthesis of α-Bromo-α-Chloro Ketones
Synlett DOI: 10.1055/s-0040-1707169 An efficient and practical protocol for the geminal heterodihalogenation of methyl ketones by using readily available dimethyl sulfoxide and a combination of HCl and HBr is reported. Control experiments suggested that the acidity of the solution, as well as the oxidizing ability and nucleophilicity of the dimethyl sulfoxide might work cooperatively in ensuring the success of the tandem substitution. Its operational simplicity, easy accessibility, and mild oxidative conditions suggest that the present strategy might be useful for the assembly of bromochloromethyl functional groups in drug...
Source: Synlett - July 1, 2020 Category: Chemistry Authors: Zhou, Jin-feng Tang, Dong-min Bian, Ming Tags: letter Source Type: research

Ligand-Free Nickel-Catalyzed Reductive Allylic Defluorinative Cross-Coupling of α-Trifluoromethyl Alkenes with Epoxides
We report a reductive allylic defluorinative reaction of α-trifluoromethyl alkenes with terminal epoxides, which consists of an iodide-mediated regioselective ring opening and a nickel-catalyzed radical-type cross-coupling, providing diverse tertiary gem-difluorobishomoallylic alcohols in moderate to high yields. Notably, this reaction is conducted under mild conditions and requires no external ligand or proton donor. [...] © Georg Thieme Verlag Stuttgart · New YorkArticle in Thieme eJournals: Table of contents  |  Abstract  |  Full text (Source: Synlett)
Source: Synlett - July 1, 2020 Category: Chemistry Authors: Lin, Zhiyang Lan, Yun Wang, Chuan Tags: cluster Source Type: research