Facile Assembly Of Sulfenylated N-heterocycles Based On Lewis Acid Activation Of Disulfides

Sulfenylated N-heterocycles are valuable building blocks and important skeletons in many natural products biologically and active pharmaceutical compounds.The choice of suitable sulfur source is of great importance for efficient synthesis of this privileged structures.Nowadays,the concept of sustainable catalysis and green chemistry has been stimulating,the development of high-atom and high-step economic methods is one of the important goals in modern organic synthesis.In this context,this dissertation studies the facile assembly of some sulfenylated N-heterocycles based on Lewis acid activation of disulfides.The main research results are summarized as follows:(1)We have realized activation of disulfides by Cu(II)Lewis acid which triggers a highly efficient electrophilic sulfenoamination of alkenes under aerobic condition,allowing access to a broad range of synthetically and biologically valuable sulfenyl Nheterocycles.This case also represents the only method available for the synthesis of alkylsulfenyl N-heterocycles in a single step.(2)Based on Cu(II)Lewis acid activation of disulfides,we have first applied Prins cyclization to the synthesis of sulfenylated 1,3-oxazinanes and oxazolidines.Importantly,DMSO serves simultaneously as a reaction medium and a surrogate of formaldehyde reactant.Mechanistic studies provide evidence that actions of Lewis acid and in situ formed sulfinic acids as a Br?nsted acid catalyst,respectively,synergistically catalyze these cyclization processes.