Unusual ionization of phosphine-boranes under RP-HPLC-HRMS conditions disclose a potential system for reduction of C=O bond

HRMS analysis of a set of phosphine-boranes using RP-HPLC-HRMS has been performed using an acetonitrile/water mixture. The data show that all compounds undergo ionization under the measurement conditions to afford cations of [M-H](+), [2M-H](+), [2M-3H](+), [2M-5H](+) or [2M 6H](2+) type. A detailed analysis of their structures led to the conclusion that these species might act as carbonyl-group activators. [GRAPHICS]