The Intermediate from the Triphenylphosphine-Tetrachloromethane-Alcohol Reaction: Relative Rates of Intermediate Formation, Kinetics, and Mechanism of Intermediate Decomposition

Document Type

Article

Publication Date

1-1-1978

Description

The rate of formation of the phosphorylated intermediate formed by reacting triphenylphosphine, carbon tetrachloride, and an alcohol is only slightly influenced by steric effects. The relative rates of intermediate formation are primary > secondary > neopentyl. The relative rates of intermediate decomposition follow the order primary > secondary > neopentyl. Thus neopentyl alcohol reacted with the phosphorylating agent at room temperature to form an intermediate without concomitant decomposition to neopentyl chloride. The structure of the intermediate was elucidated by NMR and 31P decoupling. Rates of decomposition to the respective alkyl chlorides of the phosphorylated intermediates formed from neopentyl alcohol and from l,l-dideuterio-2,2-dimethylpropanol were run at various temperatures. Clean first-order kinetics were obtained as well as the energetics for the decomposition reaction. A small positive a hydrogen kinetic isotope effect was obtained and the various mechanisms of intermediate decomposition to chloride product are discussed in terms of rate constants, the energetics, and the isotope effects.

Share

COinS