Neil J. Wilson

UNUSUALLY DIRECT SYNTHESIS OF MONO- AND DI-SUBSTITUTED TETRATHIAFULVALENES

Abstract Direct reaction of norbornadiene, tributylphosphine, carbon disulfide and acetylenic diesters affords the norbornene-fused dihydrotetrathiafulvalenes 7 in addition to the bis-adducts 4 and for less reactive acetylenic dipolarophiles only 7 is isolated. Upon flash vacuum pyrolysis the compounds 7 undergo a retro Diels-Alder reaction to give substituted tetrathiafulvalenes 8 . By using the norbornadiene diester in place of norbornadiene with DMAD, 8a can be obtained in higher overall yield. Attempted isolation of the zwitterionic structure 9 instead gave a rearrangement product with the novel 1,2,5-trithiepane stabilised ylide structure 11 .

Flash vacuum pyrolysis of dichlorophosphines over magnesium: Generation and reactivity of simple phosphinidenes

Abstract Flash vacuum pyrolysis of dichlorophosphines over magnesium at 500–600 °C gives the products expected from intramolecular CH insertion of the corresponding phosphinidenes.

Generation and reactivity of a 3H-phosphaindene: the first 3H-phosphole

Abstract By gas-phase pyrolysis over a solid base the title compound has been prepared as a 1:1 mixture with its hydration product and characterised spectroscopically; the hindered CP double bond is surprisingly unreactive.

Formation and Structure of a Novel Zwitterionic Phosphoniocyclopentenonide From Bu3P, DMAD and COS

Tributylphosphane, DMAD and carbonyl sulfide react in a 2:2:1 ratio to give Bu3PS and the crystalline adduct 2 which is stabilised by extensive delocalisation; the sulfur analogue 5 has also been obtained.

The Formation of Heterocyclic Compounds from Carbon Disulfide

Abstract Carbon disulfide has been readily available since the earliest days of organic chemistry and has proved to be a versatile building block for construction of a wide variety of heterocyclic compounds. In this review we have aimed to present the most important examples of reactions in which a heterocycle is formed either from CS2 or from a readily formed adduct such as a xanthate, dithiocarbamate, trithiocarbonate or trialkylphosphine adduct. The material is ordered so that the heterocyclic products appear in order of: (i) increasing ring size, (ii) increasing number of heteroatoms and, (iii) decreasing priority of heteroatoms.

New reactions of cyclic sulfoxides under Pummerer conditions

Reaction of the dihydrotetrathiafulvalene monosulfoxide 3 with TFAA results both in deoxygenation to give 1 and rearrangement to give the isomer 8, whose X-ray structure is presented; the corresponding disulfoxide 4 similarly rearranges to give 20.

Synthesis and Properties of a BenzoquinoneDihydrotetrathiafulvalene Diad

Abstract A new donor–acceptor diad compound 6 with the donor dihydro-TTF and acceptor quinone functions in very close proximity has been prepared and characterized. The X-ray structure shows an interesting stacking pattern and electrochemically it undergoes two reversible oxidations and two reversible reductions. An ESR signal has been observed due to thermal population of the radical anion/radical cation state.

Formation of a New Zwitterionic Phosphorus Compound using Bun 3P and COS

Abstract We have recently reported the use of the crystalline tri-n-butylphosphine-carbon disulfide adduct to form a variety of heterocyclic compounds including dithiole-containing ylides,1 2-alkylidene- 1.3-dithiolanes,2 and dihydrotetrathiafulvalenes3. In particular reaction with DMAD gave the dithiole-containing ylide shown1. We now describe the corresponding reaction of triburylphosphine and carbonyl sulfide, COS, with a variety of unsaturated systems which generally takes a completely different course as shown for the example of DMAD below. The structure of the unusual zwitterionic product has been confirmed by X-ray diffraction and is shown.