Breaking aziridines to construct morpholines with a gold(i)-catalyzed tandem ring-opening and cycloisomerization reaction†
Shuyao Zhang,Chuan Shan,Shuai Zhang,Luye Yuan,Jianwu Wang,Chen-Ho Tung,Ling-Bao Xing
Organic & Biomolecular Chemistry Pub Date : 10/27/2016 00:00:00 , DOI:10.1039/C6OB02284G
Abstract

A convenient synthetic method for the construction of morpholine derivatives from easily available aziridines and propargyl alcohols has been successfully developed. A tandem nucleophilic ring-opening of aziridine/6-exo-dig cyclization/double bond isomerization sequence was achieved by using a single gold(I) catalyst under mild conditions. The gold(I) catalyst served as a π acid and also a σ acid to realize the dual activation of both reactants in this reaction. The obtained unsaturated morpholine products could be easily hydrogenated to achieve target morpholine derivatives with good diastereoselectivities in high yields.

Graphical abstract: Breaking aziridines to construct morpholines with a gold(i)-catalyzed tandem ring-opening and cycloisomerization reaction