Synthetic applications of tris(pentafluorophenyl)borane

Abstract

(A) Hydrosilation of aromatic compounds catalyzed by 1-4 mol% of tris(pentafluorophenyl)borane is a mild and selective addition of Ph 3SiH at room temperature. Yields and conversion rates for this transformation are high and the reactivity order is esters ≫ ketone > aldehyde which is paradoxical to the normal reactivity pattern.8 (Matrix Presented) (B) Secondary benzylic alcohol derivatives undergo allylation with allylsilanes in the presence of catalytic amounts of B(C6F 5)3. Other functionalities such as bromo, acetoxy, and primary benzyloxy groups also undergo smooth allylation.10 (Matrix Presented) (C) Reduction of imines to amines is an important organic transformation. A variety of benzaldimines and ketimines are mildly and effectively hydrosilated in good to excellent yields.11 (Matrix Presented) (D) Aziridine ring opening is an important organic transformation that generates versatile nitrogen building blocks found in many biological systems. Nonactivated aziridines undergo nucleophilic ring opening with catalytic amounts of B(C6F5)3 to yield the corresponding trans-diamine.6. (Matrix Presented).