Amidinato Isopropylmethylamidosilylene‐Catalyzed Hydroboration of Carbonyl Compounds
Jiawen Lee, Jun Fan, An‐Ping Koh, Wan‐Jun Joslyn Cheang, Ming‐Chung Yang, Ming‐Der Su, Cheuk‐Wai So
Abstract
Abstract This study describes the use of an amidinato isopropylmethylamidosilylene [LSiN(Me) i Pr] ( 1 , L=PhC(N t Bu) 2 ) to catalyze hydroboration of carbonyl compounds. Compound 1 (loading: 5–10 mol%) was shown to be an efficient catalyst for the chemoselective hydroboration of aldehydes (average yield=97 %, average TOF=8.8 h −1 ) and ketones (average yield=97 %, average TOF=1.7 h −1 ) with pinacolborane (HBpin) in C 6 D 6 at 90 °C to form borate esters. Mechanistic studies show that the Si lone pair electrons on 1 and the B vacant p orbital of HBpin activates the C=O double bond of aldehydes and ketones, the intermediates of which undergoes hydroboration to yield borate esters and regenerate compound 1 .