New synthetic routes to highly-extended tetrathiafulvalenes

Abstract

Dedicated to Prof. Armand LATTES on the occasion of his 50th anniversary of teaching and research activities and for his involvement as a President of the "Société Française de Chimie" AbstractVarious synthetic routes to highly extended tetrathiafulvalene (TTF) derivatives are presented. They generally involve a (poly)olefination reaction in the last step, thanks to Wittig-type or Horner-Wadsworth-Emmons (HWE) reactions. Two complementary strategies have been carried out by reacting a (poly)formyl-TTF with a phosphorous (P-ylide or phosphonate) reagent, or on the contrary, by the preparation of (poly)phosphonate-TTF derivatives prone to react with aldehydes. An X-ray structural determination of one of these systems confirms the high π-extension of such resulting TTF derivatives.

A Fused Donor−Acceptor System Based on an Extended Tetrathiafulvalene and a Ruthenium Complex of Dipyridoquinoxaline

“…Complex 8 was soluble in acetonitrile, but this solvent was incompatible with HWE reaction conditions using butyllithium. Consequently complex 8 was added as a solid to a large excess of the phosphonate anion generated at −78 °C in tetrahydrofuran from compound 9 . The reaction mixture was allowed to warm to room temperature, and the color of the solution changed from pale yellow to bordeaux around −15 °C.…”

Oxygen, sulfur, selenium, tellurium and polonium

“…The same group also reports the synthesis and crystal structure of a new precursor for functionalised DTDAFs. 43 Reports of extended TTFs, in which the conjugated core between the two dithiole rings has been extended, include the incorporation of extra double bond(s), 44 triple bond(s), 45 para-quinoid spacer unit(s), 46 a two-way or three-way junction separating dithiole rings using a benzene ring, 47 or combinations of the above. 48 Ouahab et al report the opening of the central CQC bond in a TTF derivative by Cu 2+ salts 49 to form a 1,4,6,9-tetrathia-10-ketospiro [4,5]decane.…”

MagtrieveTM (CrO2): A Versatile Oxidant in Organic Synthesis

“…Reactions with Magtrieve TM are typically performed in chlorinated solvents or toluene. Magtrieve has found wide application in organic synthesis, such as in the oxidation of allylic alcohols to allylic aldehydes, 2 the formation of benzyl from benzoin, 3 the aromatization of imidazolines, 4 the conversion of 2-hydroxymethyl-6,7bis(pentylsulfanyl)tetrathiafulvalene into 2-formyl-6,7bis(pentylsulfanyl) tetrathiafulvalene, 5 oxidation of 2-methoxyphenols to 1,4-benzoquinones, 6 etc. This reagent is still ferromagenetic and can be conveniently removed after the reaction by a simple magnetic separation, because only the surface of the CrO 2 is reduced.…”