Tetrathiafulvalene reactions

Extended tetrathiafulvalenes with acetylenic cores are interesting compounds because of their redox and chromophoric properties. Such molecules are both interesting from materials and supramolecular chemistry perspectives. A tetraethynylethene-extended tetrathiafulvalene, for instance, was prepared using a microwave-promoted Sonogashira reaction [72]. Coup-... 

Scheme 1.32 Test reaction with tetrathiafulvalene-oxazoline ligands.

In addition, Bryce and Chesney have developed chiral oxazolines linked to tetrathiafulvalene in order to use these ligands as redox-active ligands. When applied to the test reaction, these ligands gave only low enantioselec-tivities (<21% ee), as shown in Scheme 1.32. 

A wide variety of benzotrichalcogenoles are selectively synthesized in good yields by the reactions of the corresponding benzodichalcogenastannoles with an S or Se source (Scheme 16).126 128 Unsymmetrical tetrathiafulvalenes and diselenadithiafulvalenes are prepared by the reaction of dichalcogenastannoles with esters in the presence of AlMe3.129 131... 

The l,l -diferrocenyl-VT electron donor molecule is structurally similar to diferrocenyltetrathiafulvalene but with the TTF moiety replaced by bis(vinylene-dithio)tetrathiafulvalene (VT) [76]. It has currently not been possible to separate the cis- and trans-isomers. The 1 1 polyiodide complex of l,l -diferrocenyl-VT was obtained through reaction with iodine. EPR and Mossbauer spectra indicate that in this charge transfer salt the VT moiety is oxidized while the ferrocene... 

A new effective metal-ffee radical approach by Murphy et al generates the free radical by treatment with tetrathiafulvalene (TTF).1491 As depicted in scheme 16 the aromatic amine 79 is transformed into the diazonium salt 81 which on treatment with TTF leads to the radical 82. The following stereoselective cyclization gives the hexahydrocarba-zole scaffold 80, a substructure of alkaloids like aspi-dospermidin, strychnin and vinblastin. Also the non-toxic tris(trimethylsilyl)silane was employed for domino reactions, eg. for the preparation of the alkaloid aspidospermidin. 

Previous work on the synthesis of TTF (tetrathiafulvalene) containing polymers has been reported by at least seven groups of researchers. Most of this work concerns condensation 6,7,8,9 polymers or polymers made from vinyl substituted TTF molecules . Without exception, the polymers produced by these methods have been largely unacceptable for subsequent physical study because of their brittle,intractable, highly insoluble nature. Only by reaction of a suitably monofunctionalized TTF derivative with the preformed polymer poly(vinylbenzylchloride) has it been found possible — to prepare soluble TTF homopolymers with more manageable physical properties. 

The redox reaction shown in Scheme 7.60 results in the formation of an amide a-radical and tetrathiafulvalene cation-radical. These initially formed a-radical and cation-radical combine to give salts of the S-arylated tetrathiafulvalene (a minor product) and C-alkylated tetrathiafulvalene (the main product). The latter demonstrates an unprecedented carbon-carbon bond formation with the cation-radical of tetrathiafulvalene the structure depicted was confirmed by single crystal x-ray analysis (Begley et al. 1994). 

Photoinduced intramolecular electron transfer in the donor-acceptor complex 87 (R = H) generates transient charge-separated open-shell species with the remarkably long lifetime of about 75 ps [89]. Dyads that contain Tt-extended tetrathiafulvalene units also form stable cationic species upon oxidation [90]. The dumbbell shaped triad 91 [91-93] (Scheme 4.13) was obtained by carrying out the reaction with the in situ generated bis-diene at room temperature, in the dark and in o-dichlorobenzene as a solvent in 50% yield. The product is thermally unstable and easily undergoes a retro-Diels-Alder reaction [91]. 

An unusual six-electron cycloaddition could be observed in the reaction of CgQpjg with tetrathiafulvalene (TTF) [70], TTF is not added to one of the free double bonds but replaces two of the fluorine atoms in a way that leaves the CgQpjg moiety, whose structure is described above (Figure 9.1). Under loss of F2 the product Cjq Fi6(TTF) is formed (Figure 9.7). 

CV investigations of 6-mercaptopurine and 8-mercaptoquinoline SAMs on pc-Au electrodes have been presented by Madueno et al. [186] and He etal. [187], respectively. Several model electrode reactions involving various redox probes were studied using such modified electrodes. Baunach and Kolb etal. [188] have deposited copper on disordered benzyl mercaptan film on Au(lll) surfaces. They have also studied the behavior of benzyl mercaptan SAM on Au(lll) in H2SO4 solution using CV and STM. Structural and electrical properties of SAMs based on tetrathiafulvalene derivatives on Au(lll) were investigated. These mono-layers were disordered, or at least loosely... 

Fluorinated bis(tetrathiafulvalenes), such as 51 (R = CH3 or (GH2)sCH3), undergo double t ro-substitution on reaction with thiolate anions in oxygen-free dimethylformamide (DMF) to produce the substitution products (Equation 2) <1995JA9995>. 

Tetrathiafulvalene derivatives undergo reaction with nucleophiles, such as 195, to produce the linearly-fused TTF compounds such as 51 in reasonable yields (Equation 130). A small amount of the angularly substituted regioisomer is... 

Ni(p3)(CS2)] has been found to react with hexafluorobut-2-yne and subsequently with CO giving tetrakis(trifluoromethyl)tetrathiafulvalene.231 The reaction route is shown in Scheme 1. 

A recent attempt to prepare the bis(ethylenedithio)tetrathiafulvalene derivatives fused with a 1,4-dioxane ring, viz. (89), by the Me Al-promoted reaction of organotin thiolate (87) with ester (88) was unsuccessful instead the reaction resulted110 in the production... 

In the course of exploring new synthetic routes to extended tetrathiafulvalene (TTF) derivatives, lithiation of S,S-acetals, followed by reaction with CS2 and PhCOCl, gave a-dithiomethylenes, which are possible versatile intermediates to extended TTFs. 1,2,3,5,6-Pentathiepanes 86 (Figure 25) were prepared from these intermediates <1995MI1>. 

The convergent synthesis of a range of aryl ester dendrimers with peripheral tetrathi-afulvalene units was also reported (Devonport et al. 1998). The dendrimers acquire some amount of the cation radical tetrathiafulvalene tips upon reaction with iodine in solutions. 

TTF (tetrathiafulvalene) and related compounds have been the subject of intense interest in the materials chemistry community because of their semi-conduction and superconduction properties. Recently, TTF has emerged as a unique radical initiator because its radical cation can be easily formed. The ease of formation is presumably derived from the favorable structure of the radical cation that incorporates an aromatic disulfonium salt and a very delocalized radical [49a]. Murphy et al. demonstrated a novel one-pot reaction cascade... 

Y. Sekine and E.A.H. Hall, A lactulose sensor based on coupled enzyme reactions with a ring electrode fabricated from tetrathiafulvalen-tetra-cyanoquinodimetane, Biosens. Bioelectron., 13(9) (1998) 995-1005. 

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