Phosphorous as a Nucleophile
Some assorted reactions to show the versatility of phosphorus and to exemplify the points made on page 1.
i. Shows the potency of P=O as a driving force – in the penultimate step a carbanion is created (fairly unstable) while the P=O is formed.
ii. Ph-CH2– is the only possible carbanion is the system with any stabilisation (see below), so it is the one created in the penultimate step.
i. Note the nucleophilicity of Ph3P: – able to attack and abstract Br+ from CBr4 – usually fairly inert.
ii. P=O driving force involved in the third step.
iii. The use of zinc is similar to its use in the Reformatsky Reaction (nothing to do with Phosphorus, but useful for comparison):