Darstellung, Eigenschaften und Reaktionen von Dimethyl-phenyl- und Methyl-diphenyl-methylenphosphoran / Preparation, Properties and Reactions of Dimethylphenyl- and Methyl-diphenyl-methylenephosphorane

Abstract

The ylides (CH3)2C6H5P = CH2 and CH3(C6H5),P=CH, have been prepared via their trimethylsilyl derivatives in a pure and salt-free state. Their properties and some spectroscopic data are reported. The thermal decomposition leads to the corresponding methylphenylphosphines, the addition of methanol yields a phosphine oxide and alkane or a phosphine an anisol, depending on the number of aryl groups at phosphorus. There is evidence for a pentacoordinate tetraorgano-alkoxyphosphorane as an intermediate. Protic catalysts are found to cause rapid α-proton exchange in the ylides.