The [3 + 2] cycloaddition reactions of a series of ynoate esters with a ruthenium azido complex [Ru]−N3 (1, [Ru] = (η5-C5H5)(dppe)Ru, dppe = Ph2PCH2CH2PPh2) were investigated. The reaction products, metal-bound heterocyclic complexes such as the triazolato complexes [Ru]N3C2(CO2Et)2 (2), [Ru]N3C2(CO2Et)(CF3) (3), [Ru]N3C2(CO2Me)(Ph) (4) and [Ru]N3C2(CO2Et)(CH3) (5) were produced from diethyl acetylene dicarboxylate, ethyl 4,4,4-trifluoro-2-butynoate, methyl phenylpropiolate and ethyl 2-butynoate, respectively. The complexes were all structurally characterized as being N(2)-bound. The alkylation of 2 with organic halides resulted in the cleavage of the Ru−N bond and the formation of a series of 1-alkylated-4,5-bis(ethoxycarbonyl)-1,2,3-triazoles N3(CH2R)C2(CO2Et)2 (6a, R = H; 6b, R = C6F5; 6c, R = Ph; 6d, R = 4-CH2Br-C6H4; 6e, R = 4-CN-C6H4). The high regioselective alkylation of 4 with organic halides gave a 1-alkylated-4-phenyl-5-methoxycarbonyl-1,2,3-triazoles N3(CH2C6F5)C2(Ph)(CO2Me) (N3-7a). The structures of complexes 2, 3, 4, 5 and N3-7a were confirmed by single-crystal X-ray diffraction analysis.