The reaction of allenes with phosphorus(III) compounds bearing a P-NH-(t-Bu) group: isolation of both enantiomers in crystalline form from an achiral system

Structural characterization of the tautomeric forms of the zwitterions proposed in the phosphine catalyzed transformations of electron-deficient allenes by utilizing a cyclodiphosphazane with a P-NH-t-Bu group and Ph2P(NH-t-Bu) is described. Spontaneous resolution of the products (R and S enantiomers of the crystals) via crystallization is highlighted.