A Direct, Versatile, and Chemoselective Synthesis of Vinylogous Bis- and Monourethanes/amides and β-Keto Esters by Aza-Knoevenagel-Type Reactions of Tertiary Amides with Enolates
作者:Pei-Qiang Huang、Wei Ou
DOI:10.1002/ejoc.201601326
日期:2017.1.18
carbanions generated from methyl ketones, malonic acid monoester, 2-phenylacetate, or (benzylsulfonyl)benzene. Moreover, when higher homologous of acetate was used, beta-keto esters were obtained directly from amides. The method has been applied to the one-step synthesis of several known key intermediates in the total synthesis of alkaloids and quinoline antibiotics. An efficient and mild intramolecular Friedel-Crafts
Acyl Radicals from α-Keto Acids Using a Carbonyl Photocatalyst: Photoredox-Catalyzed Synthesis of Ketones
作者:Da-Liang Zhu、Qi Wu、David James Young、Hao Wang、Zhi-Gang Ren、Hong-Xi Li
DOI:10.1021/acs.orglett.0c02351
日期:2020.9.4
Acylradicals have been generated from α-keto acids using inexpensive and commercially available 2-chloro-thioxanthen-9-one as the photoredox catalyst under visible light illumination. These reactive species added to olefins or coupled with aryl halides via a bipyridyl-stabilized Ni(II) catalyst, enabling easy access to a diverse range of ketones. This reliable, atom-economical, and eco-friendly protocol
Direct Aldehyde Csp<sup>2</sup>
−H Functionalization through Visible-Light-Mediated Photoredox Catalysis
作者:Minh Duy Vu、Mrinmoy Das、Xue-Wei Liu
DOI:10.1002/chem.201704224
日期:2017.11.13
challenge for synthetic chemists. In recent years there has been considerable interest in using selective C−Hactivation as a direct route for generating reactive intermediates. Herein, the use of visible‐light‐mediated dual photoredox organocatalysis as a mild and effective method for C −H activation of aldehydes is reported, resulting in the generation of acyl radicals. These nucleophilic acyl radical
Hydrogen Atom Transfer Reactions via Photoredox Catalyzed Chlorine Atom Generation
作者:Samantha Rohe、Avery O. Morris、Terry McCallum、Louis Barriault
DOI:10.1002/anie.201810187
日期:2018.11.26
waste‐limiting, and atom‐economical. The catalytic generation of chlorineatoms from chloride ions is one of the most challenging redox processes, where the requirement of harsh and oxidizing reaction conditions renders it seldom utilized in synthetic applications. We report the mild, controlled, and catalytic generation of chlorineatoms as a new opportunity for access to a wide variety of hydrogen atom transfer
Thiazolium-Catalyzed Additions of Acylsilanes: A General Strategy for Acyl Anion Addition Reactions
作者:Anita E. Mattson、Ashwin R. Bharadwaj、Andrea M. Zuhl、Karl A. Scheidt
DOI:10.1021/jo060699c
日期:2006.7.1
utilizing N-heterocyclic carbenes (NHCs) derived from thiazolium salts has been developed for the generation of carbonyl anions from acylsilanes. Synthetically useful 1,4-diketones and N-phosphinoyl-α-aminoketones have been prepared in good to excellent yields via NHC-catalyzed additions of acylsilanes to the corresponding α,β-unsaturated systems and N-phosphinoylimines. These organocatalytic reactions