REACTION OF METALLATED ACETYLENES WITH PHENYLSULFINYLAMINE

Abstract Lithiated alkynes or alkynylmagnesium bromides readily (THF, -30 + 30°C. 10–15 min) react with phenylsulfinylamine to form N-phenylalkynyl-1-sulfinamides in high yield. Sequential treatment of but-2-yne with butyllithium and magnesium bromide in THF at -100°C leads to the formation of not only N-phenylbut-2-yne-1-sulfinamide, but its allenic isomer, N-phenylbuta-2,3-diene-2-sulfinamide in total yield 95%. molar ratio = 2.5:1, respectively. The reaction of prop-1-yne-3-magnesium bromide with phenylsulfinylamine proceeds in diethyl ether at -100°C to afford N-phenylprop-2-yne-1-sulfinamide in 81% yield. In no case the probable cyclization is observed.