Divergent synthesis of 5- and 4-(2,1-azaborine) substituted isoxazoles via regioselective [3 + 2] cycloadditions of nitrile oxides and B-ethynyl-1,2-azaborines

Abstract

A new class of terminal alkyne reagents was developed and applied to the divergent synthesis of 5- and 4-(2,1-azaborine) substituted isoxazoles with excellent regioselectivities.