Formation of azetidines by electrophilic cyclizations have been reported, starting with homoallylic amines (4-exo mode cyclizations). We reported that the formation of these compounds can be carried out starting with allylic amines (4-endo mode cyclizations) using bis(collidine)bromonium(I) hexafluorophosphate as an electrophile. These cyclizations occur via a carbocation intermediate.
Gold(I)-Catalyzed Stereoconvergent, Intermolecular Enantioselective Hydroamination of Allenes
作者:Kristina L. Butler、Michele Tragni、Ross A. Widenhoefer
DOI:10.1002/anie.201201584
日期:2012.5.21
Gold and silver: A 1:2 mixture of [(S)‐1}(AuCl)2] and AgBF4 catalyzes the enantioselectivehydroamination of chiral, racemic 1,3‐disubstituted allenes with N‐unsubstituted carbamates to form N‐allylic carbamates in good yield, with high regio‐ and diastereoselectivity, and up to 92 % ee (see scheme, Cbz=benzyloxycarbonyl).
Gold‐Catalyzed Amine Cascade Addition to Diyne‐Ene: Enantioselective Synthesis of 1,2‐Dihydropyridines
作者:Jingwen Wei、Yangyang Xing、Xiaohan Ye、Bao Nguyen、Lukasz Wojtas、Xin Hong、Xiaodong Shi
DOI:10.1002/anie.202305409
日期:2023.8
The first example of 1,2-dihydropyridine synthesis through a formal [3+2+1] fashion utilizing gold-catalyzed intermolecular amine cascade addition to diyne-ene is reported herein, exhibiting good yield and excellent enantioselectivity.