One-step synthesis of α/β cyano-aqua cobinamides from vitamin B12 with <font>Zn(II)</font> or <font>Cu(II)</font> salts in methanol

Abstract

This short communication describes the screening of various metal salts for the preparation of cyano-aqua cobinamides from vitamin B12 in methanol. ZnCl 2 and Cu(NO 3 ) 2 ·3H 2 O have been identified as most active for this purpose and represent useful alternatives to the widely applied Ce(III) method that requires excess cyanide.