Synthesis of Alkenyl Ylide and Alkyne-coordinated Rhenium Complexes

Additions of nucleophiles like phosphines to coordinated alkynes are important processes in organometallic synthesis. In this work, exocyclic alkenyl ylide phenolate (1-2) and benzoate (5) Re(V) complexes are obtained from the reactions of internal 2-alkynylphenols, and 2-ethynylbenzoic acid with ReOCl2(OEt)(PPh3)2, respectively. The Re(V) complexes 1-2 can be reduced to η2-alkyne Re(III) complexes 3-4 with P-C bond cleavage.