α-Amino esters as nucleophiles in diastereoselective palladium catalysed allylic substitution reactions
摘要:
Allylic acetates undergo palladium catalysed allylic substitution with amino ester nucleophiles. Using enantiomerically pure cx-amino esters, the substitution products are obtained with moderate diastereoselectivity (up to 85: 15: 70% d.e.). The reactions could also be performed using an enantiomerically pure ligand, which was found to exert a stronger influence over the stereochemical outcome. (C) 1998 Elsevier Science Ltd. All rights reserved.
New amphiphilicresin-supported triarylphosphines PEP (1) were designed and prepared on polyethylene glycol-polystyrene graft copolymer (PEG-PS). Palladiumcomplexes of 1, Pd(PEP)2 (4) and Pd(PEP) (5), catalyzed allylicalkylation of 3-acetoxy-1,3-diphenyl-1-propene (6) and cinnamyl acetate (7) with various nucleophiles including 1,3-dicarbonyl compounds, amino acids, sodium azide, and sodium sulfinate