Studies On Cross-Coupling Reactions Of Sulfonyl Hydrazides

Sulfonyl hydrazides are well stable and readily available which have been widely employed to synthesize various kinds of functional compounds such as naturally occurring products,bioactive molecule and organic intermediate.They have become one of the important research object in organic synthetic chemistry.Recently,the cross-coupling reactions based on sulfonyl hydrazides are growing rapidly,the reaction type,catalyst and products of them were present diversified trend.First,sulfonyl hydrazides can be used to reduce the unsaturated bond based on the reduction properties of hydrazine group.Furthermore,hydrazones formed from sulfonyl hydrazides and aldehydes or ketones can be transfor,med to diazo compound intermediates under the base,which could proceed to a series of coupling reactions by utilizing the cabbeen mechanism.Moreover,sulfonyl hydrazides can be used as a sulfurylation and sulfuration reagents to synthesize sulfones and thioether compounds.In addition,it also can be used as an arylation or alkylation reagents to construct C-S bond and C-X bond via C-S bond cleavage.Based on the structural and nature diversity of sulfonyl hydrazides,this paper has carried out a series of research work focused on the cross-coupling reactions with sulfonyl hydrazides.The main contents are listed as the following:(1)A palladium-catalyzed desulfitative Sonogashira-type coupling between arylsulfonyl hydrazides and terminal alkynes is developed.1,2-disubstituted acetylene compounds were constructed under acid-and base-free conditions by using a catalytic amount of transition metals via an oxidative cross-coupling reaction.This reaction showed good selectivity and tolerated various functional groups.The reaction system for 1,2-disubstituted acetylene synthesis provides an simple,efficient and potential value method.(2)A general approach towards aromatic ketone compounds from arylsulfonyl hydrazides and nitrile under palladium-catalysis conditions is described.This method affords an efficient approach using low-cost nitrile and readily available arylsulfonyl hydrazides for facile construction of aromatic ketone compounds via transition metal-catalyzed C-S bond cleavage and addition reaction of polarity unsaturated bond by using molecular oxygen as a sole oxidant.