Pyrolysis of β,γ,β′-trioxo phosphorus ylides: Convenient synthesis of symmetrical and unsymmetrical diacylalkynes
作者:R.Alan Aitken、Hugues Hérion、Amaya Janosi、Swati V. Raut、Shirley Seth、Ian J. Shannon、Fiona C. Smith
DOI:10.1016/s0040-4039(00)73898-6
日期:1993.8
Flash vacuum pyrolysis of a series of 1,2,4-trioxo-3-triphenylphosphoranylidene-butane derivatives, formed by acylation of β-oxo-phosphorus ylides with α-oxo-acid chlorides, results in extrusion of Ph3PO exclusively across the 2,3-position to give diacylalkynes.
Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 5. Selective extrusion of PH<sub>3</sub>PO from β,γ,β′-trioxo ylides to give diacylalkynes
作者:R. Alan Aitken、Hugues Hérion、Amaya Janosi、Nazira Karodia、Swati V. Raut、Shirley Seth、Ian J. Shannon、Fiona C. Smith
DOI:10.1039/p19940002467
日期:——
Sixteen examples of the previously unknown trioxo ylides 7 have been prepared by acylation of stabilised phosphorus ylides 8 with alpha-oxo acid chlorides 9. Extrusion of Ph(3)PO from these is readily achieved using FVP at 500 degrees C in most cases, to afford the diacylalkynes 10 in moderate yield. Three examples failed to give the expected alkynes and the nature of the processes involved in these cases is uncertain. Fully assigned C-13 NMR spectra are presented for the ylides and an unexpected pattern is observed in the value of J(p-c) for the three carbonyl carbons depending on the nature of the substituents present. There is some correlation between the value of (2)J(p-c) for the central carbonyl carbon and the success of the pyrolysis although this is not complete. The method has been used to prepare a specifically C-13 labelled acetylenic diester 14.
Synthesis and reactivity of 2-halo-2H-azirines towards nucleophiles
作者:Teresa M.V.D. Pinho e Melo、Cláudia S.J. Lopes、António M.d'A.Rocha Gonsalves
DOI:10.1016/s0040-4039(00)01239-9
日期:2000.9
Aitken R. Alan, Herion Hugues, Janosi Amaya, Karodia Nazira, Raut Swati V+, J. Chem. Soc. Perkin Trans. 1, (1994) N 17, S 2467-2472
Structure and photochemical behaviour of 3-azido-acrylophenones: a matrix isolation infrared spectroscopy study
作者:Susy Lopes、Cláudio M. Nunes、Andrea Gómez-Zavaglia、Teresa M.V.D. Pinho e Melo、Rui Fausto
DOI:10.1016/j.tet.2011.07.084
日期:2011.10
characterized both structurally and spectroscopically, and its photochemistry used to probe the mechanism of photo-induced conversion of 3-azido-acrylophenones into oxazoles. In situ UV irradiation (λ = 235 nm) of matrix-isolated MACBP yielded as primary photoproduct a 2H-azirine, which undergoes subsequent photoisomerization to methyl 4-chloro-5-phenyl-1,3-oxazole-2-carboxylate. In a competitive process, a ketenimine