A reaction exemplifying migration of boron-substituted carbon is described. We show that alpha-boroalkyl groups of transient boroalkyl acyl azide intermediates readily migrate from carbon to nitrogen. This process allows access to a new class of stable molecules, alpha-boryl isocyanates, from alpha-borylcarboxylic acid precursors. The methodology facilitates synthesis of a wide range of alpha-aminoboronic acid derivatives, including alpha,alpha-disubstituted analogues.