New simple syntheses of (E)-1-azido- (or thiocyanato)-alk-1-enes from alk-1-ynes by hydroboration

Abstract

Stereochemically pure (E)-1-azido- (or thiocyanato)-alk-1-enes have been synthesized in situ and in reasonable yields from alk-1-ynes upon hydroboration with disiamylborane followed by reactions with simple reagents; sodium azide (or potassium thiocyanate) and copper(II) nitrate trihydrate, in the presence of copper(II) acetate and a small amount of water, in polar aprotic solvents.