Numerous electrophilic thiocyano oxyfunctionalization reactions of alkenes have been achieved using N-thiocyano-dibenzenesulfonimide, which is a newelectrophilic thiocyanation reagent and could be easily prepared in two steps from dibenzenesulfonimide. This approach provides efficient, simple, and modular methods for the formation of SCN-containing heterocycles such as lactones, tetrahydrofurans,
Diastereoselective Radical Aminoacylation of Olefins through N-Heterocyclic Carbene Catalysis
作者:Wen-Deng Liu、Woojin Lee、Hanyu Shu、Chuyu Xiao、Huiwei Xu、Xiangyang Chen、Kendall N. Houk、Jiannan Zhao
DOI:10.1021/jacs.2c11209
日期:2022.12.14
There have been significant advancements in radical-mediated reactions through covalent-based organocatalysis. Here, we present the generation of iminyl and amidyl radicals via N-heterocyclic carbene (NHC) catalysis, enabling diastereoselective aminoacylation of trisubstituted alkenes. Different from photoredox catalysis, single electron transfer from the deprotonated Breslow intermediate to O-aryl
Regio- and Enantioselective Catalytic δ-C–H Amidation of Dioxazolones Enabled by Open-Shell Copper-Nitrenoid Transfer
作者:Suhyeon Kim、Se Lin Song、Jianbo Zhang、Dongwook Kim、Sungwoo Hong、Sukbok Chang
DOI:10.1021/jacs.3c05258
日期:2023.7.26
>19:1 rr and >99:1 er). Combined experimental and computational mechanistic studies unveiled that the open-shell character of the postulated Cu-nitrenoids enables the regioselective hydrogen atom abstraction and subsequent enantio-determining radical rebound of the resulting carbon radical intermediates. The synthetic utility of this asymmetric cyclization was demonstrated in the diastereoselective introduction
A dual bio-/photocatalytic system has been developed for achieving previously elusive diastereo- and enantioselective radical lactonizations. By integrating directed evolution and photoinduced single-electron oxidation, we repurposed engineered ene-reductases to steer non-natural radical C−O formations giving a diverse array of enantioenhanced 5- and 6-membered lactones with vicinal stereocenters,