Use of electrogenerated highly reactive zinc in facile synthesis of 2-arylpropenoic acid esters and anti-inflammatory agents

摘要

Highly reactive zinc metal was prepared by electrolysis of a DMF solution containing naphthalene and a supporting electrolyte in a one-compartment cell fitted with a platinum cathode and a zinc anode. The reaction of this reactive zinc with ethyl 2-bromoacrylate at -20 °C and the following cross-coupling reaction with aryl iodides or aryl bromides in the presence of 5 mol% of Pd(P(o-Tol)_3)_2Cl_2 at 70 °C gave the corresponding ethyl 2-arylpropenoates in almost quantitative yields. These cross-coupling reactions were successfully applied to a synthesis of several anti-inflammatory agents such as ibuprofen or naproxen.