The importance of the Lewis base in lithium mediated metallation and bond cleavage reaction of allyl amines and allyl phosphines.

Metallation of two analogous N- and P-allyl molecules Ph2NCH2CHCH2 and Ph2PCH2CHCH2 with nBuLi have shown contrasting reactivities based on the choice of Lewis donor. With metallation of the alpha carbon atom was achieved regardless of the Lewis donor used while in comparison metallation of showed an unexpected donor denticity dependence with P-C bond clevage induced with the tri-dentate PMDETA. Complementary DFT and solution studies rationalise this outcome.