Desymmetrization of Prochiral Cyclopentenes Enabled by Enantioselective Palladium-Catalyzed Oxidative Heck Reaction
作者:Guihua Chen、Jian Cao、Qian Wang、Jieping Zhu
DOI:10.1021/acs.orglett.9b04357
日期:2020.1.3
catalytic amount of Pd(TFA)2 and a chiral Pyox ligand under oxygen atmosphere, oxidative Heck reaction between arylboronic acids and 4-substituted or 4,4-disubstituted cyclopent-1-enes afforded the chiral arylated products with concurrent creation of two stereocenters in good yields with excellent diastereo- and enantioselectivities.
This work gives an in depth account of our dominocarbopalladation‐carbonylation method for substrates possessing β‐hydrogens. The scope of the method is examined for allylic amines containing trisubstituted olefins and we detail our attempts toward the diastereospecific synthesis of contiguous quaternary centers using this technology. The results give key insights into the relative rates of the competing
Intramolecular 1,5-H transfer reaction of aryl iodides through visible-light photoredox catalysis: a concise method for the synthesis of natural product scaffolds
The intramolecular 1,5-H transfer reaction of the aryl radicals generated from unactivited aryl iodides by photocatalysis is described. The features of this transformation are operational simplicity, excellent yields, mild reaction...
mild visible‐light‐induced Pd‐catalyzed intramolecular C−H arylation of amides is reported. The method operates by cleavage of a C(sp2)−O bond, leading to hybrid aryl Pd‐radical intermediates. The following 1,5‐hydrogen atom translocation, intramolecular cyclization, and rearomatization steps lead to valuable oxindole and isoindoline‐1‐one motifs. Notably, this method provides access to products with
nitrenium (NHN) salts, the analogues of N-heterocyclic carbenes, have attracted considerable interest. However, relatively little is known about their catalytic ability beyond their Lewis acid catalysis. Herein, we describe that NHNs can serve as catalytic electron acceptors for charge transfer complex photoactivations. We showcase that, under blue light irradiation, the NHN salts could catalyze the