TETRAHEDRON LETTERS Tetrahedron Letters 44 (2003) 9275–9278 Pergamon Synthesis and characterization of TTF-type precursors for the construction of conducting and magnetic molecular materials S. Bouguessa, a A. K. Gouasmia, a S. Golhen, b L. Ouahab b and J. M. Fabre a, * a Laboratoire de chimie organique: He ´te ´rochimie et mate ´riaux organiques, UMR 5076, ENSCM, 8, rue de l’e ´cole normale, 34296 Montpellier cedex 5, France b Laboratoire de chimie du solide et inorganique mole ´culaire, UMR 6511, CNRS Universite ´ de Rennes 1, Institut de Chimie de Rennes, 35042 Rennes cedex, France Received 12 September 2003; revised 7 October 2003; accepted 13 October 2003 Abstract—New TTF precursors for the construction of conducting and magnetic materials have been synthesized by using the palladium-catalyzed cross-coupling reaction between a mono- or a bis(trialkylstannyl)tetrathiafulvalene and a series of heteroaryl halides. The redox potential and some crystallographic data of these new building blocks are presented and discussed. © 2003 Elsevier Ltd. All rights reserved. One of the current objectives in the field of conducting molecular materials derived from tetrathiafulvalene (TTF) is to try to correlate within the same solid two distinct physical properties 1 such as magnetic and con- ducting properties, 2 seeking to establish in this case a magnetic coupling between the conduction electrons and the spins. 3 These materials could be obtained start- ing from precursors containing both a TTF unit as source of conducting electrons and a pyridine-type het- erocycle as a ligand of a transition metal carrying a localized spin. The work achieved until now in this area is sparse. 4,5 We present here the synthesis, the redox properties and some crystallographic data of a series of conjugated and compact precursors of type 3, 4 and 5 which could give access to salts manifesting the required spin-electron correlations. 1. Synthesis Although the 4,5-dimethylthio-4-(4-pyridyl)tetrathia- fulvalene was recently prepared by a cross-coupling reaction of the corresponding 1,3-dithiole-2-thiones, 6 the poor yield obtained (15%) suggests the use of the organometallic strategy described by Iyoda and co- workers 7,8 because it recently led to the 4,4,5-trimethyl- 5-(pyridyl)tetrathiafulvalene in 63% yield. 9 We thus chose to develop this strategy to prepare compounds of type 3 and 4 from several heterocyclic halides contain- ing nitrogen atom(s) and to extend it to the synthesis of disubstituted TTF derivatives of type 5 by using, as a new intermediate, a bis-trialkylstannyl-TTF derivative (2c) (Scheme 1). In the first step of the process, the mono and bis-tri- butylstannyl-TTF derivatives 2a–c, were respectively prepared by the successive treatment of TTFs 1a–c with LDA and tributyltin chloride at -78°C in dry THF. According to the degree of substitution of the starting TTF 1a–c, 1.2, 1.5 and 3 equiv. of these reagents were used respectively to lead, after column chromatography purification (SiO 2 , pentane–CH 2 Cl 2 9.5:0.5), to the expected compounds 2a (70%), 2b (79%) and 2c (76%). * Corresponding author. 0040-4039/$ - see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.tetlet.2003.10.067