Triphenylvinylphosphonium salts

Triphenylvinylphosphonium salts are usually used as dipolarophiles against azides and diazoalkanes30. 2,3-Diphenyl-2//-azirine and 1-azido-l-phenylpropene as precursors of 2-methyl-3-phenyl-2H-azirine produce, after irradiation, 2,5-diphenylpyrrole and 2-methyl-5-phenylpyrrole, respectively29. 

Electronegatively substituted acetylenes afford triphenylvinylphosphonium salts analogously in high yields but under somewhat more energetic conditions.65 In the absence of acid the primary adducts of aromatic phosphines to acetylenes readily undergo further reactions.66,67... 

Pyrazolinyltriphenylphosphonium salts (88) can be prepared by 1,3-dipolar addition of excess diazomethane to triphenylvinylphosphonium salts. Thermolysis of (88) gave phosphonium salts (89) by elimination... 

Additions to Vinylphosphonium Salts. Two reports of the reaction of -mercaptoketones with triphenylvinylphosphonium bromide in the presence of base to yield 2,5-dihydrothiophens (86) have appeared. -... 

Triphenylvinylphosphonium bromide undergoes cydoaddition with a variety of dienes to give phosphonium salts, e.g. (90). ... 

The formation of a stable 1,2-oxaphospholan from the sodium salt of benzoin and triphenylvinylphosphonium bromide has been extended to substituted vinylphosphonium salts, diastereoisomers being obtained in some cases. 

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