I have been making a conscious effort to find ways to use borohydride compounds rather than just default to the mighty gray sledge hammer- LAH. There are numerous reports of diverse and wonderful means of activating borohydride to reduce the more refractory functional groups. Recently I prepared and used Zn(BH4)2 on a new substrate. Initially, it appears to work poorly. The grey wall cake seems to contain metallic zinc. If preferences mattered, I’d prefer see electrons reducing my substrate rather than Zn (II) to Zn.

You can’t always get what you want.     M. Jagger