Asymmetric hydrogenation of α-keto ester with diamine-complexed metal

✍ Scribed by Catherine Pinel; Nelly Gendreau-Diaz; Alexandra Bréhéret; Marc Lemaire

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 396 KB
• Volume: 112
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/1381-1169(96)00148-3

✦ Synopsis

Asymmetric catalytic hydrogenation of methyl phenylglyoxylate with diamine-chelated metal was studied. Enantiomeric excesses of up to 50% were obtained using a rhodium complex prepared in situ by mixing bis(l,5-cyclooctadiene)dirhodium(I) dichloride with two equivalents of (N,N')dimethyl

(1 R,2R)diphenylethylene diamine la in methanol. The e.e. decreases by using aqueous solvent. However, when cyclodextrin was added in MeOH/H,O (70/30); similar e.e. to that observed in pure methanol was obtained. Application in biphasic medium could be envisaged.