Generation of(E)-β-trifluoromethyl vinylsulfonohydrazides under photocatalysis and their anti-bacteria activity

Trifluoromethylation/sulfonylation of alkynes from trifluoromethyl thianthrenium triflate and sulfur dioxide under extremely mild reaction conditions provides a facile access to trifluoromethyl-substituted vinyl sulfonohydrazides in moderate to good yields.This multicomponent reaction of trifluoromethyl thianthrenium triflate,alkynes,sulfur dioxide and hydrazines proceeds efficiently under visible light irradiation in the presence of photocatalyst at room temperature with broad substrate scope and excellent functional group compatibility.This reaction is highly stereoselective,and only(E)-isomers are obtained.Additionally,these trifluoromethyl-substituted vinyl sulfonohydrazides are further evaluated for anti-bacteria activity.In vitro activities of these compounds against Staphylococcus aureus(G+)and Escherichia coli(G-)are examined.