Phosphorous as a Nucleophile

Some assorted reactions to show the versatility of phosphorus and to exemplify the points made on page 1.

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.

2.

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):

3.Phosphines: (“P“)