The First General Method for the Synthesis of Transition-Metal π Complexes of an Electronically Diverse Family of 1,2-Azaborolyls

A general method for the synthesis of new
families of transition-metal-free 1,2-azaborolides (3) has
been developed, based on a readily available precursor
(1). These azaborolides react with a variety of transition-metal electrophiles to produce an unprecedented array
of η5-azaborolyl adducts (4) (substituents bound to
boron:  nitrogen, oxygen, hydrogen, carbon, and phosphorus).