13273-33-1Relevant academic research and scientific papers
The value of 2JP–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides
Aitken, R. Alan,Boubalouta, Youcef,Chang, Da,Cleghorn, Lee P.,Gray, Ian P.,Karodia, Nazira,Reid, Euan J.,Slawin, Alexandra M.Z.
, p. 6275 - 6285 (2017/09/29)
A survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the C[dbnd]P to C[dbnd]O torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also conform to this pattern. The value of 2JP–CO is then correlated with whether or not thermal extrusion of Ph3PO occurs to give alkynes for over 200 ylides and an empirical rule developed that the extrusion never occurs for ylides where this value is > 11 Hz. This is used to rationalise the anomalous behaviour of some trioxo ylides and cyclic ylides, two of which afford cycloalkynes, isolated after rearrangement as the isomeric 1,3-dienes. The rule also holds for a family of novel highly fluorinated ylides which afford fluorinated alkynes in good yield upon flash vacuum pyrolysis.
Reactions with Organophosphorus Compounds, XLV. A New Synthesis of (2-Oxocycloalkylidene)triphenylphosphoranes
Oehler, Elisabeth,Zbiral, Erich
, p. 2326 - 2331 (2007/10/02)
The bromoenolethers 1, upon treatment with triphenylphosphorane in nitromethane, yield the cycloalkenylphosphonium salts 4, which on subsequent reaction with hydrochloric acid and sodium carbonate afford the (2-oxocycloalkylidene)phosphoranes 3.With methyl bromide the O-methyl derivatives 4 are reformed from compounds 3; with acetyl azide the condensed acyltriazoles 5 are obtained, which lead to the unsubstituted triazoles 6, when treated with KOH.Reaction of 3b with (SCN)2 yields the cycloheptene derivative 7b, which can be cyclized to the thiazole 8b.
