Enantiomerically pure phosphaalkene-oxazolines (PhAk-Ox): synthesis, scope and copolymerization with styrene.

The design of a synthetic route to a class of enantiomerically pure phosphaalkene-oxazolines (PhAk-Ox) is presented. The condensation of a lithium silylphosphide and a ketone (the phospha-Peterson reaction) was used as the P=C bond-forming step. Attempted condensation of PhC(=O)Ox (Ox = CNOCH(iPr)CH(2)) and MesP(SiMe(3))Li gave the unusual heterocycle (MesP)(2)C(Ph)=CN-(S)-CH(iPr)CH(2)O (3).

Chiral induction via the disassembly of diruthenium(II,III) tetraacetate by chiral diphosphines.

[Ru(2)(μ-O(2)CCH(3))(4)(MeOH)(2)](PF(6)) reacts with chiral diphosphines (R,R)- and (S,S)-chiraphos, leading to disassembly and production of the enantiomers Λ-[Ru(η(2)-O(2)CCH(3))(η(2)-(R,R)-chiraphos)(2)](PF(6)) and Δ-[Ru(η(2)-O(2)CCH(3))(η(2)-(S,S)-chiraphos)(2)](PF(6)) in high yield and purity. X-ray crystallography and solid-state circular dichroism (CD) show that only the indicated isomers are present in the solid state. Solution CD measurements also indicate their predominance in solution.