ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Kinetics of catalytic Meerwein-Ponndorf-Verley reduction of aldehydes and ketones using boron triethoxide

Burcu Uysal and Birsen S. Buyuktas

Department of Chemistry, Akdeniz University, 07058 Antalya, Turkey

E-mail: bbirsen@akdeniz.edu.tr

Received: 30 April 2009  Revised: 19 August 2009  Accepted: 20 August 2009

Abstract: Catalytic Meerwein-Ponndorf-Verley (MPV) reduction of various aliphatic, aromatic, and unsaturated aldehydes and ketones to corresponding alcohols (analyzed by GC-MS) in the presence of boron triethoxide (B(OEt)₃) were studied. Kinetics of this reduction reaction was also studied and the respective rate constants were determined. It was found that B(OEt)₃ catalyzes the reduction of aliphatic aldehydes and ketones to alcohols at room temperature while aromatic aldehydes and ketones were not reduced under the same conditions. In addition, MPV reduction using B(OEt)₃ was found to be chemoselective as unsaturated aldehydes and ketones afforded the corresponding alcohols without affecting unsaturated groups. The mechanism proposed involves a six-membered transition state in which both the alcohol and the carbonyl are coordinated to the same boron centre of a boron alkoxide catalyst.

Keywords: boron triethoxide - chemoselective reduction - aldehydes - ketones - Meerwein-Ponndorf-Verley reduction

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-009-0098-3

Chemical Papers 64 (1) 123–126 (2010)