Phosphinines 1,3,5-triphenyl

Phosphole sulfides reacted with diazoalkanes to give homophospholes which were transformed to phosphinines. Thus, 3,4-dimethyl-l-(methylsulfanyl)phosphole 1-sulfide on heating with ethyl diazoacetate reacted to give the homophosphole which rearranged on treatment with triphenyl phosphite to afford ethyl 4,5-dimethylphosphinine-2-carboxylate in good yield (Table 4). ... 

After the first synthesis of a P-phosphinin derivative, the 2,4,6-triphenyl compound (1) <66AG(E)846>, and the isolation of the unsubstituted phosphinin (2) <7UA3293>, a dramatic development and an avalanche of publications followed. 

The most significant results were obtained by the group of Breit who demonstrated that phosphinine rhodium(I) complexes behave as very efficient catalysts. In the first two reports, most efforts focused on the hydroformylation of styrene and important conversion yields and interesting selectivities in favour of the branched aldehyde were obtained by using derivatives of 2,4,6-triphenylphosphin-ine 1 [51]. Importantly, reactions could be carried out under mild conditions in toluene at 25 °C using [Rh(acac)(CO)2] complex as catalytic precursor with a Rh phosphinine substrate ratio of 1 5 280 and a CO/H2 (1 1) pressure of 20 bars. With the triphenyl derivative, a Turn Over Frequency (TOF) of 28.7 mol sub-strate/mol catalyst/h was obtained, the conversion yield reaching 30.8%. Theses... 

Scheme 19). Other phosphinines have also been prepared by strong heating of the triphenyl-phosphole in the presence of an alkyne <82JOC2376>. 

At least three names are available for the compound H3P=CH2. These are phosphine methylene, methylene phosphonium ylid and phosphonium methylide moreover, the compound can be classed as a phosphorane The compound PhjP Rj may be called triphenylphosphonium methylide, tri-phenylphosphonium methanide or triphenyl-methylenephosphorane. The pyridine analogue, C5H5P, has been known variously as phosphobenzene, phosphabenzene, phosphorin, and most recently, phosphinine. The term phosphane for (1) in Table 1.4 and its derivatives is the most recent and the most systematic, but it is difficult to see how the more widespread and firmly rooted term phosphine will ever be replaced. In addition, adoption of the term phosphane would put it in line with such little-used terms as carborane for CH4, nitrane for NH3 and oxane for HjO. 

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