Efficient and selective cleavage of the t-butoxycarbonyl group from di-t-butylimidodicarbonate using catalytic bismuth(III) bromide in acetonitrile

Di-t-butylimidodicarbonates can be chemoselectively and efficiently deprotected to the corresponding mono-BOC-protected amines in high yields using a catalytic amount of bismuth(III) bromide in acetonitrile at room temperature. This method is mild and compatible with the presence of a wide range of functional and other protecting groups in the substrates, such as TBDMS, MOM and mono-BOC or Cbz-protected amines, etc. The method has advantages of ease of operation and use of nontoxic and inexpensive catalyst.