Base-Promoted Hydroalkylation Reactions of 1,3,5-Me3C6H3, p-MeC6H4CHMe2, C6Me6, p-MeC6H4Me, and MeC6H5 Ligands Coordinated to Ruthenium(II)

The [(η 6 -arene)RuCl 2 ] 2 (arene = 1,3,5-Me 3 C 6 H 3 ( 1 ), p -MeC 6 H 4 CHMe 2 ( 2 ), C 6 Me 6 ( 3 ), p -MeC 6 H 4 Me ( 4 ), MeC 6 H 5 ( 5 )) dimers react with diphenylvinylphosphine (DPVP) to produce [(η 6 -1,3,5-Me 3 C 6 H 3 )Ru(DPVP)Cl 2 ] ( 1a ), [(η 6 - p- MeC 6 H 4 CHMe 2 )Ru(DPVP) Cl 2 ] ( 2a ), [(η 6 -C 6 Me 6 )Ru(DPVP)Cl 2 ] ( 3a ), [(η 6 - p -MeC 6 H 4 Me)Ru(DPVP)Cl 2 ] ( 4a ), and [(η 6 -MeC 6 H 5 )Ru(DPVP)Cl 2 ] ( 5a ). In acetonitrile, compounds 1 − 5 undergo base-promoted hydroalkylation reactions with potassium tert -butoxide and diphenylvinylphosphine to produce [{η 6 -3,5-Me 2 C 6 H 3 -1-CH 2 CH 2 CH 2 P(C 6 H 5 ) 2 }RuCl 2 ] ( 1b ), [{η 6 - p -Me 2 CHC 6 H 4 CH 2 CH 2 CH 2 P(C 6 H 5 ) 2 }RuCl 2 ] ( 2b ), [{η 6 -C 6 Me 5 CH 2 CH 2 CH 2 P(C 6 H 5 ) 2 }RuCl 2 ] ( 3b ), [{η 6 - p -MeC 6 H 4 CH 2 CH 2 CH 2 P(C 6 H 5 ) 2 }RuCl 2 ] ( 4b ), and [{η 6 -C 6 H 5 CH 2 CH 2 CH 2 P(C 6 H 5 ) 2 }RuCl 2 ] ( 5b ). The reaction with the p- MeC 6 H 4 CHMe 2 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.