The use of optically active O-alkyl ester hydrochlorides of L-phenylalanine and L-tyrosine as chiral micellar media for the catalysis of diels-alder reactions

Abstract

The effect of a range of O-alkyl ester hydrochloride surfactants derived from L-phenylalanine and L-tyrosine as catalysts on the Diels-Alder reaction between cyclopentadiene and methyl acrylate was studied. Both chain lengths (C₈-C₁₄) and head groups of the surfactants were found to influence the yield and selectivity of the Diels-Alder product. The C₁₀ derivatives of both phenylalanine and tyrosine surfactants gave the highest yields and selectivity. Phenylalanine ester hydrochlorides showed better catalytic activity than the tyrosine derivatives. Adduct optimum yield was obtained at a concentration relating to their critical micelle concentration (CMC) values. The Diels-Alder reaction was also found to be favored in acidic condition (pH 3) as well as in the presence of lithium chloride (LiCl) as salting out agent.

KEY WORDS: Diels-Alder, Chiral catalysts, Phenylalanine, Tyrosine, Micelle, CMC

Bull. Chem. Soc. Ethiop. 2017, 31(3), 509-518.  

DOI: http://dx.doi.org/10.4314/bcse.v31i3.15