Catalyst-free alcoholysis of phosphane-boranes: a smooth, cheap, and efficient deprotection procedure

Catalyst-free alcoholytic deprotection of borane-protected phosphorus compounds offers a smooth, efficient, and clean alternative to existing deprotection methods. In this paper we report our results on the general applicability of deprotecting phosphane- and phosphite-borane adducts by means of simple alcoholysis without the use of molecular sieves as a catalyst. Phosphane-boranes bearing at least one aromatic substituent are readily deprotected in high yields. Borane complexes of trialkylphosphanes or phosphites, however, cannot be deprotected in this way. The main merit of our method is its simplicity: apart from evaporation of the solvent, no further work-up or purification is needed.