OXIDATIVE DIMERIZATION OF DIETHYL 3-THIENYLMALONATE BY HIGH-VALENT METAL-SALTS, SYNTHESIS OF BENZO[1,2-B-4,5-B']DITHIOPHENE DERIVATIVES

Authors
CITTERIO A SEBASTIANO R MARONATI A VIOLA F FARINA A
Citation
A. Citterio et al., OXIDATIVE DIMERIZATION OF DIETHYL 3-THIENYLMALONATE BY HIGH-VALENT METAL-SALTS, SYNTHESIS OF BENZO[1,2-B-4,5-B']DITHIOPHENE DERIVATIVES, Tetrahedron, 52(41), 1996, pp. 13227-13242
Citations number
43
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
52
Issue
41
Year of publication
1996
Pages
13227 - 13242
Database
ISI
SICI code
0040-4020(1996)52:41<13227:ODOD3B>2.0.ZU;2-D
Abstract
The oxidation of diethyl 3-thienylmalonate (1) by metal oxidants (Fe(C lO4)(3), Mn(OAc)(3), MnO2 and CuO) in various solvents at 60 degrees C affords dimerization products arising from side-chain and nuclear cou pling of the intermediate delocalized malonyl radicals 6. Metal to sul phur binding is suggested to play a role in controlling the distributi on of dimers 2-5. The higher thermodynamic stability of unsymmetric di mer 3, along with its oxidative intramolecular 1,6-cyclization to 4, a llows to develop a new simple synthesis of benzo[1,2-b:4,5-b']dithioph ene derivatives 15-18. Copyright (C) 1996 Published by Elsevier Scienc e Ltd.