Borane complexes of phosphorus compounds, a very common oxidation-free relay for catalytic ligands (phosphines, phosphites, and phosphinites), can be easily deprotected by treatment with polymer-supported piperazine or N-methylpiperazine. Deprotection conditions have been optimized for the different types of phosphorus compounds, and the resulting solutions can be used without any intermediate work-up or purification process.
Work-Up-Free Deprotection of Borane Complexes of Phosphines, Phosphites, and Phosphinites with Polymer-Supported Amines
Synlett 2006, 2585-2588.