Collect. Czech. Chem. Commun. 1994, 59, 2095-2102

Regioselectivity of Complexations of Substituted Phenyl Benzoates and Phenyl Phenylacetates with Cr(CO)6

Pavol Hrnčiar, Peter Černák, Vladimír Gajda and Štefan Toma

Department of Organic Chemistry, Comenius University, 842 15 Bratislava, Slovak Republic


Selectivity of complexation of substituted phenyl benzoates is very low. In most cases, comparable yields of both regioisomeric complexes are isolated. Exception is 4-chlorophenyl ester, where benzoic acid moiety is complexed nearly exclusively. Very high regioselectivity of complexation was observed with substituted phenyl phenylacetates. The substituent of substituted phenols has not any effect on the complexation, and only phenylacetic acid moiety is complexed. This observation supports the recently proposed mechanism of the catalytic activity of the esters at arene complexation.