Selective cleavage of Cbz-protected amines.

Under conditions of catalytic Ni(0) and in most cases just over 1 equiv of Me(2)NH.BH(3)/K(2)CO(3) or Cs(2)CO(3), a Cbz-protected nitrogen, which is part of a heteroaromatic ring, can be chemospecifically cleaved without affecting a Cbz group on an originally basic amine. [reaction: see text]