Abstract

New three-coordinate and electronically unsaturated aluminum hydride [LAlH]+ [HB(C6 F5 )3 ]- (LH=[{(2,6-iPr2 C6 H3 N)P(Ph2 )}2 N]H) and aluminum methyl [LAlMe]+ [MeB(C6 F5 )3 ]- cations have been prepared. The quantitative estimation of Lewis acidity by Gutmann-Beckett method revealed [LAlH]+ [HB(C6 F5 )3 ]- to be better Lewis acid than B(C6 F5 )3 and AlCl3 making these compounds ideal catalysts for Lewis acid-mediated reactions. To highlight that the work is of fundamental importance, catalytic hydroboration of aliphatic and aromatic aldehydes and ketones have been demonstrated. Important steps of the catalytic cycle have been probed by using multinuclear NMR measurements, including successful characterization of the proposed aluminum benzyloxide cationic intermediate, [LAl-O-CH2 Ph]+ [HB(C6 F5 )3 ]- . The proposed catalytic cycle has been found to be consistent with experimental observations and computational studies clearly indicating the migration of hydride from cationic aluminum center to the carbonyl carbon is the rate-limiting step of the catalytic cycle.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.