One-step Barton decarboxylation by micellar catalysis – application to the synthesis of maleimide derivatives†
Abstract
Maleimides being studied or used in various applications, for the first time, a facile entry to Barton decarboxylation in aqueous media is described to obtain in one step substituted N-phenylmaleimide synthons. The radicals, generated by the ultrasonic lysis of N-hydroxy-2-thiopyridone esters, reacted respectively with electron deficient olefin phenylmaleimide in a one-step radical addition. These esters were obtained from natural fatty acid derivatives including unsaturated ones. Various activating conditions (UV, sonication, heating, microwaves), reactants and solvent adjustment, as well as surfactants were tested to improve the yield of the reaction. One of the products obtained was then transformed into a new electron-trap monosubstituted maleimide and was able to react again to obtain a disubstituted N-phenylmaleimide derived from biomass.