No abstract

Aminophosphines of the general structure R,P*NHR' (R = Ph or OEt; R' = Ph or Pr") react rapidly with carbon tetrachloride and bromotrichloromethane to give phosphinimines R,P(X): NR' (X = Br, or CI) and chloroform. The reaction proceeds by initial reaction on positive halogen followed by deprotonation of the phosphonium salt. In addition to chloroform, low yields of carbon tetrachloride and bromodichloromethane were detected in the reaction with bromotrichloromothane, showing that the trichlorornethyl carbanion is formed in the free state.PHOSPI~INES are known to react readily with polyhalogen compounds, usually by nucleophilic displacement on positive halogen, whereas the corresponding reactions of trialkyl phosphites are generally regarded as freeradical pr0cesses.l Thus, triphenylphosphine reacts with carbon tetrachloride a t normal temperatures,2 and exothermically with the t e t r a b r ~m i d e . ~ These reactions were considered to lead to the corresponding dihalogenomethylenephosplioranes, which were not isolated but converted directly into the dihalogeno-2Ph,P + CX, Ph3PX, + Ph,P:CX, (X = CI or Br)

Diethyl N-phenylphosphoramidite reacts with benzaldehyde and with cyclohexanone to give the corresponding a-anilinophosphonate, togetherwith a mixture of diethyl phosphonate and the anil. N-Phenyldiphenylphosphinous amide gives the a-anilinophosphine oxide with benzaldehyde, but the anil with cyclohexanone since the intermediate secondary phosphine oxide decomposes to the biphosphine monoxide in this case. Possible mechanisms for these reactions are briefly discussed. PHOSPHINES are normally unreactive towards aldehydesSimilarly trialkyl phosphites and ketones give a-hydrand ketones except in acidic solution when a-hydroxy-oxyphosphonates in the presence of weak acids by a methyl phosphonium salts are formed according to type of Arbusov r e a ~t i o n . ~ In cold alcoholic solution, the equilibrium :