The scope and limitations of the synthesis of unsymmetrically substituted TTF derivatives via the “phosphonate way” was investigated using as precursors 1,3-dithiol-2-yl-phosphonates and 1,3-dithiol-2-yliden iminium salts with various substitutents on the dithiole cycles.
We studied the influence of acetic acid concentration on the deamination and dephosphonylation of the adduct resulting of the nucleophilic reaction between adequate alpha-metalated phosphonate and imminium salt, to enhance the yield of such reactions in order to access efficiently a lot of unsymmetrical TTF derivatives. A mechanism is proposed for the formation of TTF, including steps, i(1) to i(7) The potential concurrent formation of phosphonate (1) under bar and other by-products is also discussed (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
GIMBERT, YVES;MORADPOUR, ALEC;BITTNER, SHMUEL, TETRAHEDRON LETT., 31,(1990) N, C. 1007-1010