William B. Hughes

Studies in phosphinemethylene chemistry : XIII. Routes to triphenylphosphine-halomethylenes and -dihalomethylenes☆

Abstract The action of phenyllithium on (bromomethyl)triphenylphosphonium bromide results in a nearly equimolar mixture of triphenylphosphinebromomethylene (formal H ÷ abstraction) and triphenylphosphinemethylene (formal Br ÷ abstraction). With (iodomethyl)triphenylphosphonium iodide a mixture of triphenylphosphineiodomethylene and triphenylphosphinemethylene is formed in which the latter is favored by a factor of about three. A new route to haloolefins based on phenyl(halomethyl)mercurial reagents is summarized by the equations below (X  Cl and Br). C 4 H 3 HgCX 2 Br ÷ (C 6 H 5 ) 3 P ÷ RR′CO → RR′CCX 2 ÷ C 6 H 5 HgBr ÷ (C 6 H 5 ) 3 PO C 6 H 5 HgCHXBr ÷ (C 6 H 5 ) 3 P ÷ RR′CO → RR′CCHX ÷ C 6 H 5 HgBr ÷ (C 6 H 5 ) 3 PO