Phosphaallyl complexes of Ru(ii) derived from dicyclohexylvinylphosphine (DCVP)

Abstract

The complexes [(η⁵-RC₅H₄)Ru(CH₃CN)₃]PF₆ (R = H, CH₃) react with DCVP (DCVP = Cy₂PCHCH₂) at room temperature to produce the phosphaallyl complexes [(η⁵-C₅H₅)Ru(η¹-DCVP)(η³-DCVP)]PF₆ (1) and [(η⁵-MeC₅H₄)Ru(η¹-DCVP)(η³-DCVP)]PF₆ (2). Both compounds react with a variety of two-electron donor ligands displacing the coordinated vinyl moiety. In contrast, we failed to prepare the phosphaallyl complexes [(η⁵-C₅Me₅)Ru(η¹-DCVP)(η³-DCVP)]PF₆, [(η⁵-MeC₅H₄)Ru(CO)(η³-DCVP)]PF₆ and [(η⁵-C₅Me₅)Ru(CO)(η³-DPVP)]PF₆ (DPVP = Ph₂PCHCH₂).The compounds [(η⁵-MeC₅H₄)Ru(CO)(CH₃CN)(DPVP)]PF₆ and [(η⁵-C₅Me₅)Ru(CO)(CH₃CN)(DPVP)]PF₆ (12) react with DMPP (3,4-dimethyl-1-phenylphosphole) to undergo [4 + 2] Diels–Alder cycloaddition reactions at elevated temperature. Attempts at ruthenium catalyzed hydration of phenylacetylene produced neither acetophenone nor phenylacetaldehyde but rather dimers and trimers of phenylacetylene. The structures of the complexes described herein have been deduced from elemental analyses, infrared spectroscopy, ¹H, ¹³C{¹H}, ³¹P{¹H} NMR spectroscopy and in several cases by X-ray crystallography.