Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst: applications and mechanism thereof
作者:Eduardo de Pedro Beato、Daniele Mazzarella、Matteo Balletti、Paolo Melchiorre
DOI:10.1039/d0sc02313b
日期:——
detail a strategy that uses a commercially available nucleophilic organic catalyst to generate acyl and carbamoyl radicals upon activation of the corresponding chlorides and anhydrides via a nucleophilic acyl substitution path. The resulting nucleophilic radicals are then intercepted by a variety of electron-poor olefins in a Giese-type addition process. The chemistry requires low-energy photons (blue
Quinim: A New Ligand Scaffold Enables Nickel-Catalyzed Enantioselective Synthesis of α-Alkylated γ-Lactam
作者:Xianqing Wu、Jingping Qu、Yifeng Chen
DOI:10.1021/jacs.0c07126
日期:2020.9.16
Herein, we report a nickel-catalyzedreductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone with broad substrate scope and high ee. The current art of synthesis still remains challenging on the enantioselective α-monoalkylation of pyrrolidinones. The newly designed chiral 8-quinoline imidazoline ligand
在此,我们报告了镍催化的 3-丁烯基氨基甲酰氯与伯烷基碘的还原交叉偶联反应,以获得具有广泛底物范围和高 ee 的手性 α-烷基化吡咯烷酮。目前的合成技术对吡咯烷酮的对映选择性 α-单烷基化仍然具有挑战性。新设计的手性 8-喹啉咪唑啉配体(Quinim)对于保持反应性和对映选择性至关重要,以确保单取代烯烃的还原环化,从而前所未有地合成手性非芳香杂环。
Generation and Cyclization of Unsaturated Carbamoyl Radicals Derived from <i>S</i>-4-Pentynyl Carbamothioates under Tin-Free Conditions
The radicalreaction of benzenethiol with S-4-pentynyl carbamothioates provides a valuable protocol for the tin-free generation of carbamoylradicals, which arise from intramolecular substitution at sulfur by the initial sulfanylvinyl radicals. This procedure can be usefully employed to achieve N-benzylcarbamoyl radical 5-exo and 4-exo cyclizations leading, respectively, to pyrrolidinones and azetidinones
β-unsaturated lactams starting from alkenylchloroformamides has been developed. The reaction was complete within five minutes at 150 ˚C in N-methylpyrrolidone with a catalytic amount of HBr under microwave irradiation. Not only six-membered lactams, but also five- and seven-membered lactams were obtained in high yields. lactam- cyclization - electrophilic addition -acid catalyst - microwave