Syntheses of complexes containing substituted 4-ethynylquinolines or 1-azabuta-1,3-dienes by addition of imines to a cationic butatrienylidene-ruthenium complex

Abstract

Reactions of [Ru(=C=C=C=CH2)(PR3)2Cp]+ (R=Ph or OMe) with arylimines ArN=CH(C6H4R) afford either substituted quinolines, Ru{CCC9H4RN(Ar)}(PR3)2Cp, by attack of the terminal carbon of the butatrienylidene ligand at the imine carbon, followed by C-C bond formation between the ortho carbon of the N-aryl group and Cγ of the unsaturated carbene, or 1-azabuta-1,3-dienyl complexes, formed by cycloaddition of the N=CH group to Cγ=Cδ of the carbene, followed by opening of the resulting four-membered ring. Some product dependence on the nature of the substituents in the N- and C-aryl groups is found. The N atoms in the products are strongly basic, being readily protonated, methylated or aurated. The molecular structures of nine complexes are reported, together with that of a new modification of RuCl{P(OMe)3}2Cp. © 1999 Elsevier Science S.A.