Base-promoted hydroalkylation reactions of 1,3,5-Me3C6H3, p-MeC6H4CHMe2, C6Me6, p-MeC6H4Me, and MeC6H5 ligands coordinated to ruthenium(II)

The [(eta(6)-arene)RuCl2](2) (arene = 1,3,5-Me3C6H3 (1), p-MeC6H4CHMe2 (2), C6Me6 (3), p-MeC6H4Me (4), MeC6H5 (5)) dimers react with diphenylvinylphosphine (DPVP) to produce [(eta(6)-1,3,5-Me3C6H3)Ru(DPVP)Cl-2] (1a), [(eta(6)-p-MeC6H4CHMe2)Ru(DPVP) Cl-2] (2a), [(eta(6)-C6Me6)-Ru(DPVP)Cl-2] (3a), [(eta(6)-p-MeC6R4Me)Ru(DPVP)Cl-2] (4a), and [(eta(6)-MeC6H5)Ru(DPVP)-Cl-2] (5a). In acetonitrile, compounds 1-5 undergo base-promoted hydroalkylation reactions with potassium tert-butoxide and diphenylvinylphosphine to produce [{eta(6)-3,5-Me2C6H3-1-CH2CH2CH2P(C6H5)(2)}RuCl2] (1b), [{eta(6)-p-Me2CHC6H4CH2CH2CH2P(C6H5)(2)}RuCl2] (2b), [{eta(6)- C6Me5CH2CH2CH2P(C6H5)(2)}RuCl2] (3b), [{eta(6)-p-MeC6H4CH2CH2CH2P(C6H5)(2)}RuCl2] (4b), and [{eta(6)-C6H5CH2CH2CH2P(C6H5)(2)}RuCl2] (5b). The reaction with the p-MeC6H4CHMe2 complex proceeds regioselectively at the methyl-group to produce the most stable product. All the complexes have been characterized spectroscopically and the crystal structures of several of them have been obtained.