Retrosynthetic Simplicity
Conclusions [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - November 9, 2023 Category: Chemistry Authors: Levin, Mark D. Tags: synpacts Source Type: research
Practical Site-Selective Oxidation of Glycosides with Palladium(II) Acetate/Neocuproine
Synlett DOI: 10.1055/a-2186-1485 The palladium-catalyzed oxidation of the secondary C(3) hydroxy group of glycopyranosides has set a mark in the selective modification of unprotected carbohydrates. The preformed catalyst [(neocuproine)PdOAc]2(OTf)2 oxidizes di- and oligosaccharides, as well as monosaccharides. Here, we provide a more convenient protocol for this reaction in which the Pd catalyst is formed in situ from Pd(OAc)2 and neocuproine in methanol at 50 °C. Together with a simplified product isolation, this protocol was applied to a series of mono- and disaccharides, and has been applied on a 10 gram scale. The pro...
Source: Synlett - November 9, 2023 Category: Chemistry Authors: Reintjens, Niels R. M. Bartels, Imke M. A. Marinus, Nittert Massmann, Sarina C. Bunt, Daan V. Walvoort, Marthe T. C. Witte, Martin D. Minnaard, Adriaan J. Tags: cluster Source Type: research
Synthesis of 2,4-Disubstituted Oxazoles by a Copper-Catalyzed [3+2] Annulation/Olefination Cascade between Amides and IIII/PV Hybrid Ylides
We report a novel and efficient method for oxazole synthesis through a copper-catalyzed [3+2] annulation/olefination cascade between readily available iodonium–phosphonium hybrid ylides and amides. An unprecedented α-phosphonium Cu carbenoid acts as the key intermediate. This method features excellent regioselectivity with mild reaction conditions and a broad substrate scope. Its synthetic utility is demonstrated by its application in late-stage functionalizations and the rapid synthesis of a chiral ligand based on an oxazole motif. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thie...
Source: Synlett - November 6, 2023 Category: Chemistry Authors: Ye, Xingchen Wang, Zhaofeng Tags: letter Source Type: research
Molybdenum-Catalyzed Directed Activation of Aryl Chlorides and Fluorides
Synlett DOI: 10.1055/a-2187-9441 A low-valent molybdenum species generated by the reduction of a molybdenum precursor with phenylmagnesium bromide catalytically cleaves a C–Cl or C–F bond in an aromatic ketone under mild conditions, followed by cyclization to produce a hydroxyphthalan (1,3-dihydro-2-benzofuran-1-ol) derivative. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - November 6, 2023 Category: Chemistry Authors: Banerjee, Somsuvra Matsushita, Naoki Nakamura, Eiichi Patil, Nitin T. Asako, Sobi Ilies, Laurean Tags: letter Source Type: research
Chromium-Promoted Dearomative (Deutero)Hydrocyanoalkylation of (Hetero)Arenes Using Simple Alkylnitriles
Synlett DOI: 10.1055/a-2185-0581 Herein, a general strategy for the regioselective dearomative 1,2-hydrocyanoalkylation of chromium-bound (hetero)arenes with simple alkylnitriles as pronucleophiles was disclosed, providing rapid access to 1,3-cyclohexadienes possessing useful alkylnitrile groups. The versatility of this methodology further enabled a selective dearomative deuteration reaction. Finally, synthetic applications of the method in the formal synthesis of natural products, including erysotramidine, demethoxyerythratidinone, and morphine, were demonstrated. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stu...
Source: Synlett - November 6, 2023 Category: Chemistry Authors: Zeng, Wei-Long Jiang, Xu Li, Wei Tags: cluster Source Type: research
Photoinduced Metal-Free Arylboration of Unactivated Alkenes: Synthesis of Indoline Boronic Ester
We described a photoinduced metal-free arylboration of unactivated alkenes for the synthesis of indoline boronic esters and 1,2,3,4-tetrahydroquinoline boronic ester in good yields. This approach showed good compatibility and great efficiency for a range of allylphenylamines as well as alkylamine. Remarkably, this transformation also suggested that the base is not necessary for photosensitizer-free diboron reagent mediated mild generation of aryl radical. Furthermore, compared to previously reported methods, this approach is mild and environmentally benign. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, ...
Source: Synlett - November 3, 2023 Category: Chemistry Authors: Lu, Ji He, Yangsen Ren, Lixu Li, Daling Pan, Xianchao Yang, Lin Wang, Jun Wei, Siping Wei, Jun Tags: letter Source Type: research
Visible-Light-Mediated Intramolecular Lactonization of Benzylic C(sp3) –H Bonds Promoted by DDQ and tert-Butyl Nitrite
Synlett DOI: 10.1055/a-2185-4286 A functionalization of benzylic C(sp3)–H bonds was established through a mild metal-free intramolecular lactonization protocol in the presence of DDQ/tert-butyl nitrite as photocatalysts, allowing practical and low-cost access to a series of phthalide products in moderate to excellent yields. Compared with many existing methodologies, this visible-light-driven process exhibits an excellent substrate scope and fascinating features, including the formation of water as the sole byproduct, an abundant and green energy source, commercially available catalysts, and room-temperature reaction. Fi...
Source: Synlett - November 3, 2023 Category: Chemistry Authors: Hu, Miaomiao Yang, Jiangyu Niu, Mengyu Li, Chunmei Xu, Meng Li, Meichao Shen, Zhenlu Tags: letter Source Type: research
Iridium-Catalyzed Ligand-Controlled Semi-Reduction of Alkynes Employing H2O as the Hydrogen Donor and Its Application
Synlett DOI: 10.1055/s-0042-1751516 An iridium-catalyzed ligand-controlled semi-reduction of alkynes employing H2O as the hydrogen donor, together with its application, is reported. The use of di-tert-butylphosphinous chloride is crucial for stereoselectivity toward Z-olefins, whereas the use of 2-(diphenylphosphino)benzaldehyde is crucial for stereoselectivity toward E-olefins. More than 35 alkenes were obtained in good yields and high stereoselectivities. The utility of the current method in practical applications was investigated by studying the drug effects of (E)-1,3-dimethoxy-5-styrylbenzene on nerve growth in a zebr...
Source: Synlett - November 2, 2023 Category: Chemistry Authors: Zhao, Wei Zhou, Siyi Wang, Chengniu Zhang, Yi Xu, Dawei Tags: letter Source Type: research
Diastereoselective Cross-Dehydrogenative Coupling Reactions of Amides with Diarylmethanes Using DDQ through Oxidative C –H Benzylic Activation
This study reports the chiral-auxiliary-controlled diastereoselective dehydrogenative coupling of diarylmethanes with amides by using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone as the oxidant. The scope of the proposed reaction is very broad, with a wide variety of substrates and nucleophiles being applicable. The chiral induction can be attributed to the coordination of the oxygen atom on the chiral auxiliary with the carbocation intermediates. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - November 2, 2023 Category: Chemistry Authors: Kimura, Nagisa Nakata, Kenya Tags: letter Source Type: research
Total Synthesis of Mavacuran Alkaloids via Bioinspired and Non-Bioinspired Strategies
Conclusion7 Epilogue [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - November 2, 2023 Category: Chemistry Authors: Kouklovsky, Cyrille Poupon, Erwan Evanno, Laurent Vincent, Guillaume Tags: account Source Type: research
Total Synthesis of Marine Macrolide Natural Products by the Macrocyclization/Transannular Pyran Cyclization Strategy
Conclusions [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - November 2, 2023 Category: Chemistry Authors: Fuwa, Haruhiko Tags: account Source Type: research
Construction of Bibenzothiophenes through Oxidative C –H Cyclization with 1,3-Diynes
Synlett DOI: 10.1055/s-0042-1751514 The development of concise and efficient methods to construct bithiophene derivatives is an appealing task in the fields of organic chemistry and organic functional materials. Herein, we summarize our recent efforts towards the development of catalytic oxidative C–H cyclization reactions of thiophenol derivatives with 1,3-diynes, which provides a straightforward and effective synthetic approach to both symmetrical and nonsymmetrical 3,3′-bibenzothiophenes. This work is expected to stimulate the application of catalytic oxidative C–H annulation of aromatics with 1,3-diynes for the e...
Source: Synlett - October 31, 2023 Category: Chemistry Authors: Chen, Jingyi Lei, Tao Wan, Danyang Yang, Yudong Tags: synpacts Source Type: research
A Golden Synthetic Approach to 2-(1H-Pyrrol-1-yl)anilines and Pyrrolo[1,2-a]quinoxalines through a Gold Carbene Intermediate
Synlett DOI: 10.1055/a-2159-9400 The pyrrolo[1,2-a]quinoxaline skeleton has significant potential for many biological and optical applications. Hence, in this study, unconjugated ynone derivatives were treated with 1,2-diaminoarenes in a gold-catalyzed cyclization to give 2-(1H-pyrrol-1-yl)anilines, which are valuable starting materials, and pyrrolo[1,2-a]quinoxalines by a one-pot and single-step approach. A reaction mechanism for the formation of the pyrrolo[1,2-a]quinoxaline skeleton featuring a key gold carbene intermediate is proposed. On the other hand, the methyl group on the C-2 position of the 2-(1H-pyrrol-1-yl)ani...
Source: Synlett - October 31, 2023 Category: Chemistry Authors: Tasdemir, Volkan Gen ç, Hasan Menges, Nurettin Tags: letter Source Type: research
Bis(2-ethylhexyl)amine as an Effective Organocatalyst for the Racemic Reactions of α,β-Unsaturated Aldehydes Involving an Iminium Ion
Synlett DOI: 10.1055/a-2179-5916 Bis(2-ethylhexyl)amine is shown to be a suitable organocatalyst to prepare racemic compounds in the reactions of α,β-unsaturated aldehydes involving an iminium ion, whereas diphenylprolinol silyl ether is a well-known chiral organocatalyst for the asymmetric versions of the same reactions. The generality and limitations of bis(2-ethylhexyl)amine are disclosed. [...] Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals: Table of contents | Abstract | Full text (Source: Synlett)
Source: Synlett - October 31, 2023 Category: Chemistry Authors: Hayashi, Yujiro Han, Xiaolei Mori, Naoki Tags: cluster Source Type: research
Pd-catalyzed Stereodivergent [4+2] Annulation to Access [6.7]-Fused N-Heterocycles
Synlett DOI: 10.1055/a-2184-6373 Stereodivergent synthesis of N-heterocycle frameworks bearing 1,3-nonadjacent stereogenic centers through a single transformation remains a high-priority challenge in organic synthesis. Herein, we highlight our recent discovery of stereodivergent access to such useful structural motifs using Pd-catalyzed [4+2] annulation reactions of vinyl benzoxazinaones and seven-membered cyclic N-sulfonyl aldimines. A wide range of N-heterocycles with 1,3-nonadjacent stereogenic centers were obtained in high efficiency and stereodivergency. Importantly, the polarity of solvents was found to play a key ro...
Source: Synlett - October 30, 2023 Category: Chemistry Authors: Ma, Zhan-Cai Huang, Yuan Tags: synpacts Source Type: research
