Reactivity study of arene(azido)ruthenium N-O-base complexes with activated alkynes

Substitution reactions of chloro ?6-arene ruthenium N-O-base complexes [(?6-arene)Ru(N-O)Cl] [N-O = pyrazine-2-carboxylic acid (pca-H), 8-hydroxyquinoline (hq-H); arene = p-iPrC6H4Me, N-O = hq (1); arene = C6Me6, N-O = hq (2)] with NaN3 yield neutral arene ruthenium azido complexes [(?6-arene)Ru(N-O)N3] [N-O = pca, arene = p-iPrC6H4Me (3), arene = C6Me6 (4); N-O = hq, arene = p-iPrC6H4Me (5), arene = C6Me6 (6)]. These complexes undergo [3 + 2] dipolar cycloaddns. with the activated alkynes di-Me and di-Et acetylenedicarboxylate to yield the arene triazole complexes [(?6-arene)Ru(N-O){N3C2(CO2R)2}] [N-O = pca, R = Me, arene = p-iPrC6H4Me (7), C6Me6 (8); R = Et, arene = p-iPrC6H4Me (9), C6Me6 (10); N-O = hq, R = Me, arene = p-iPrC6H4Me (11) C6Me6 (12); R = Et, arene = p-iPrC6H4Me (13), C6Me6 (14)]. On the basis of a proton NMR study, the adducts of ruthenium N-O-base complexes with di-Me acetylenedicarboxylate are assigned as the N(2) isomers while the adducts with di-Et acetylenedicarboxylate are assigned as the N(1) isomers. All complexes have been characterized by IR and NMR spectroscopy as well as by elemental anal. The structures of the azido complexes [(?6-p-iPrC6H4Me)Ru(pca)N3] (3), [(?6-p-iPrC6H4Me)Ru(hq)N3] (5) and [(?6-C6Me6)Ru(hq)N3] (6) were detd. by single crystal X-ray diffraction. [on SciFinder(R)]