Study On The Sulfuration Of Propargylamion And Alkynyl Oxime Ether

Nitrogen and sulfur are two indispensable elements in life,which widely exist in natural products and pharmaceutical molecules.Many heterocycles containing nitrogen and sulfur atoms exhibit significant physiological and pharmaceutical activities.Cleavage of C-N bond could generate synthons with carbon and nitrogen atoms,which is an important method for the synthesis of carbon and nitrogen-containing compounds.Elemental sulfur,as an odorless and relatively safe sulfur source,could be widely used for the synthesis of various sulfur compounds under base.In this paper,the synthesis of 1,2-dithio-3-thiones,thioamides,and isothiazole disulfides were respectively studied through the tandem C-N bond cleavage and sulfuration of propargylamine and alkynyl oxime ether using elemental sulfur as the sulfur source.This paper is mainly divided into four parts:(1)The C-N bond cleavage and the synthesis of five-membered heterocycles with nitrogen and sulfur atom was summarized;(2)The reaction of propargylamine with elemental sulfur to synthesize 1,2-dithio-3-thione derivatives was studied.The reaction involves the cleavage of C-N bond and the formation of multiple C-S bonds and furnishes 1,2-dithio3-thiones in good to excellent yield.Various groups are tolerant under the reaction conditions;(3)The reaction of propargyl compound with elemental sulfur to synthesize thioamides was studied.Through the hydrolysis of C-C triple bond and formamide,the C-N bond and the C-S double bond were formed smoothly in a one-pot;(4)The reaction of alkynyl oxime ether and elemental sulfur to isothiazolyl disulfide was studied.The reaction involves the cleavage of N-O bond and the formation of multiple C-S and N-S bonds,which provides an effective way for the synthesis of isothiazole disulfides.