273205-07-5Relevant academic research and scientific papers
Reactions of vanadium(V) and tantalum(V)-complexes with kinetically stabilized phosphaalkynes. A simple synthesis of 1,3,4-thia and 1,3,4-selenadiphospholes
Peters, Christoph,Fischbeck, Uwe,Tabellion, Frank,Regitz, Manfred,Preuss, Fritz
, p. 44 - 51 (2007/10/03)
A simple synthetic pathway to the unknown 1,3,4-thiadiphospholes 3 and 1,3,4-selenadiphospholes 4 has been developed involving reactions of the azaphosphavanada(V)-cyclobutenes 2, generated in situ from the imidovanadium(V) complex tBuN = VCl3 and the phosphaalkynes 1a-d, with an excess of elemental sulfur or grey selenium, respectively. The reactions of the phosphaalkynes 1a,b with TaOCl3 or VOCl3·DME furnish the 1,2-dichloro-phosphaalkenes 5a,b and 1,2,3,4-tetrachloro-3,4-di-tert-butyl-1,1-diphosphethane 7a. The metallacyclic species 2e-h with secondary or primary alkyl groups on the ring nitrogen atom are unstable and undergo quantitative conversion to the 1H-1,2,4-azadiphospholes 8, whereas in the presence of an excess of phenylacetylene the 1H-1,2-azaphospholes 9e-h, are formed selectively. A catalytic reaction course has been demonstrated for the cyclotrimerization of phenylacetylene and 2-butyne initiated by small amounts of TaSCl3. The syntheses of the vanadium(IV) complexes [tBuN = VCl2·2Py] and [tBuN = VCl2·TMEDA] are also described starting from tBuN = VCl3 and phosphaalkene 12.
Chemistry and ligating properties of the 1,2,4-thiadiphosphole P2SC2Bu2t
D'Arbeloff-Wilson, Sarah E.,Hitchcock, Peter B.,Nixon, John F.,Nyulászi, László
, p. 7 - 15 (2007/10/03)
New synthetic routes to the 1,2,4- and 1,3,4-thiadiphospholes, P2SC2Bu2,t, are presented. Both η1-W(CO)5 and η5-M(CO)3 complexes (M = Mo, W) of the 1,2,4-thiadiphosphole ring are described and the molecular structure of the former determined by a single crystal X-ray study is in good agreement with theoretical calculations. The thermal conversion of the η1-M(CO)5 complex to the η5-M(CO)3 complex is attributable to the entropy change in the reaction. A sequence of [4 + 2] and [2 + 2 +2] cyclo-addition reactions of the 1,2,4-thiadiphosphole, P2SC2Bu2t, with the phosphaalkyne, P≡CBut, affords the tetracyclic cage compound P4SC4Bu4t which has also been structurally characterised.
Syntheses and theoretical and mechanistic aspects of 1-thia-2,4- and 1- thia-3,4-diphosphole formed from CS2 and (t)BuCP and crystal and molecular structure of the first 1-thia-3,4-diphosphole complex: Cis- [{PtCl2(PEt3)}2(P2SC2(t)Bu2)]
D'Arbeloff-Wilson, Sarah E.,Hitchcock, Peter B.,Krill, Steffen,Nixon, John F.,Nyulaszi, Laszlo,Regitz, Manfred
, p. 4557 - 4562 (2007/10/03)
The reaction of (t)BuCP with CS2 (or its ylide type complexes such as R3PCS2 (R = Et, Ph, cyclohexyl), (C5H10N)2CCS2, or (C4H8NO)2CCS2) gives a mixture of 3,5-di-tert-butyl-1-thia-2,4-diphosphole and 2,5-ditert- butyl-1-thia-3,4-diphosphole, which were characterized by NMR spectroscopy. The latter was also characterized by the single-crystal X-ray structure determination of its bis(platinum(II)) complex [(PtCl2PEt3)2(μ- P2SC2(t)Bu2)]. This is the first structural characterization of a 1-thia- 3,4-diphosphole ring. The mechanism of these reactions was explored by B3LYP/6-311+G** level quantum chemical calculations. The reaction pathway involves a phosphadithiolediylcarbene and its diphosphatetrathiafulvalene dimer as intermediates. Several other possible reaction pathways were ruled out.
