Enantioselective Copper(I)/Chiral Phosphoric Acid Catalyzed Intramolecular Amination of Allylic and Benzylic C−H Bonds
作者:Liu Ye、Yu Tian、Xiang Meng、Qiang‐Shuai Gu、Xin‐Yuan Liu
DOI:10.1002/anie.201911742
日期:2020.1.13
radical-involved enantioselective intramolecular C(sp3 )-H amination of not only allylic positions but also benzylic positions with broad substrate scope. The use of 4-methoxy-NHPI (NHPI=N-hydroxyphthalimide) as a stable and chemoselective HAT mediator precursor is crucial for the fulfillment of this transformation. Preliminary mechanistic studies indicate that a crucial allylic or benzylic radical intermediate
Enantioselectivebromolactonization of trisubstituted olefinicacids producing synthetically useful chiral lactones with two contiguous asymmetric centers has remained mainly unexplored except for the 6‐exo cyclization mode. In this work, the 5‐exo‐ and 6‐endo modes of bromocyclization of trisubstituted olefinicacids were enabled for the first time using N‐bromosuccinimide and a pyridyl phosphoramide
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