Synthesis, molecular structure, substitution and C–C coupling reactions of ruthenium complexes containing (η 5-C 9H 7)Ru(PPh 3) as a molecular unit

Abstract

The 2-methallyl complex [(η 5-C 9H 7)Ru(η 3-2-MeC 3H 4)(PPh 3)] ( 3), prepared from [(η 5-C 9H 7)Ru(PPh 3) 2Cl] ( 2) and 2-MeC 3H 4MgCl, reacts with HX (X = Cl, CF 3CO 2) in the presence of ethene to give the chiral-at-metal compounds [(η 5-C 9H 7)Ru(C 2H 4)(PPh 3)X] ( 4, 5) in nearly quantitative yields. Treatment of 2 with AgPF 6 and ethene affords [(η 5-C 9H 7)Ru(C 2H 4)(PPh 3) 2]PF 6 ( 6), which reacts with acetone to give the substitution product [(η 5-C 9H 7)Ru(OCMe 2)(PPh 3) 2]PF 6 ( 7). The molecular structure of 7 has been determined crystallographically. Whereas treatment of 4 with CH(CO 2Et)N 2 yields the olefin complex [(η 5-C 9H 7)Ru{η 2-( Z)-C 2H 2(CO 2Et) 2}(PPh 3)Cl] ( 8), the reactions of 4 and 5 with Ph 2CN 2, PhCHN 2 and (Me 3Si)CHN 2 lead to the formation of the carbeneruthenium(II) derivatives [(η 5-C 9H 7)Ru( CRR′)(PPh 3)Cl] ( 9– 11) and [(η 5-C 9H 7)Ru( CRR′)(PPh 3)(κ 1-O 2CCF 3)] ( 12– 14), respectively. Treatment of 9 (R = R′ = Ph), 10 (R = H, R′ = Ph) and 11 (R = H, R′ = SiMe 3) with MeLi produces the hydrido(olefin) complexes [(η 5–C 9H 7)RuH(η 2-CH 2 CPh 2)(PPh 3)] ( 15), [(η 5-C 9H 7)RuH(η 2-CH 2 CHPh)(PPh 3)] ( 18a, b) and [(η 5-C 9H 7)RuH(η 2-CH 2 CHSiMe 3)(PPh 3)] ( 19) via C–C coupling and β-hydride shift. The analogous reactions of 11 with PhLi gives the η 3-benzyl compound [(η 5-C 9H 7)Ru{η 3-(Me 3Si)CHC 6H 5}(PPh 3)] ( 20). The η 3-allyl complex [(η 5-C 9H 7)Ru(η 3-1-PhC 3H 4)(PPh 3)] ( 17) was prepared from 10 and CH 2 CHMgBr by nucleophilic attack.