Asymmetric Hydrogenation of 3, 4-Methylenedioxy-α-acetamidocinnamic Acid Using Newly Developed Silica Gel-Supported Chiral Rhodium (I) -Phosphine Complexes

• Published in: Chemical & pharmaceutical bulletin Vol. 35; no. 5; pp. 1686 - 1690
• Main Authors: ISHIZUKA, NAOYASU, TOGASHI, MASAHIRO, INOUE, MASAMI, ENOMOTO, SABURO
• Format: Journal Article
• Language: English
• Published: TOKYO The Pharmaceutical Society of Japan 1987; Pharmaceutical Soc Japan; Maruzen
• Subjects: 3, 4-methylenedioxy-α-acet-amidocinnamic acid; asymmetric hydrogenation; Chemistry; Chemistry, Medicinal; Chemistry, Multidisciplinary; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; L-DOPA; Life Sciences & Biomedicine; Organic chemistry; Pharmacology & Pharmacy; Physical Sciences; Preparations and properties; rhodium complex; Science & Technology; silica gel; solid catalyst; Adsorption; Rhodium Complexes; Asymmetric reaction; Bicyclic compound; Organic ligand; Aromatic compound; Silica gel; Dehydroaminoacid; Transition metal Complexes; Oxygen heterocycle; Hydrogenation; Catalyst
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.35.1686

The asymmetric hydrogenation of 3, 4-methylenedioxy-α-acetamidocinnamic acid was carried out in the presence of a chiral Rh (I) -complex of (2S, 4S) -N-butoxycarbonyl-4-diphenylphosphino-2-diphenylphosphinomethylpyrrolidine (BPPM) adsorbed on hydrophobic silica gel in MeOH- H2O solvents. Excellent conversions (100%) and a high optical yield (85%) were attained with [Rh (COD) BPPM] +ClO4- on methylated silica gel. The adsorption of the complex was improved byintroducing a stearoyl group instead of the butoxycarbonyl group of BPPM. When the recovered catalysts were reused three times, the optical yields decreased gradually from 85 to 69%.