Oxidative dimerization of diethyl 3-thienylmalonate by high valent metal salts. Synthesis of benzo [1, 2-b: 4, 5-b′] dithiophene derivatives

A Citterio, R Sebastiano, A Maronati, F Viola, A Farina

Index: Citterio, Attilio; Sebastiano, Roberto; Maronati, Antonietta; Viola, Fabio; Farina, Alessandra Tetrahedron, 1996 , vol. 52, # 41 p. 13227 - 13242

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Citation Number: 7

Abstract

The oxidation of diethyl 3-thienylmalonate (1) by metal oxidants (Fe (ClO4) 3, Mn (OAc) 3, MnO2 and CuO) in various solvents at 60° C affords dimerization products arising from side- chain and nuclear coupling of the intermediate delocalized malonyl radicals 6. Metal to sulphur binding is suggested to play a role in controlling the distribution of dimers 2–5. The higher thermodynamic stability of unsymmetric dimer 3, along with its oxidative ...