Five-membered metallacycloallene compounds, 1-zirconacyclopenta-2,3-dienes 1, derived from but-1-en-3-ynes 2 and low-valent zirconocene, reacted with esters and isocyanates. Reactions of 1 with carboxylic esters such as ethyl acetate and methyl benzoate resulted in the formation of alkynyl ketones after hydrolysis, albeit in low yields, and diethyl carbonate gave alkynyl esters in moderate yields. Insertion of isocyanates such as phenylisocyanate to the Zr–C bond of 1 afforded an alkynyl amide when 1 had substituents at the 2,4-positions (1a), while the zirconium complexes 1 that had silyl groups at the 2,5-positions, 1b and 1c, gave dienyl amides after hydrolysis. These reactions involved C=O insertion into the Zr-Csp³ bond in 1. It is likely that the insertion afforded seven-membered 1-oxa-2-zirconacyclohepta-3,4-diene intermediates first, whilst the reaction of 2,5-disilyl-1-zirconacyclopenta-2,3-dienes 1b-c with isocyanates formed five-membered 1-oxa-2-zirconacyclopent-3-ene intermediates. Additional C–C bond formation reactions of these intermediates via transmetallation to copper salts followed by addition of allyl halides furnished allylated products.

衍生自丁-1-烯-3-炔2和低价锆茂的五元金属亚环戊烯化合物1-氧化锆环戊-2,3-二烯1与酯和异氰酸酯反应。的反应1与羧酸酯，如乙酸乙酯和苯甲酸甲酯导致水解后形成炔酮的，尽管在产量低，和碳酸二乙酯在中等产率得到的炔基酯。当1在2,4-位（1a）上具有取代基时，而在2,5-位具有甲硅烷基的锆配合物1上，将异氰酸酯（如苯基异氰酸酯）插入1的Zr–C键可得到炔基酰胺，1b和1c，水解后得到二烯基酰胺。这些反应涉及将C = O插入Zr-C sp ³键1中。插入可能首先提供了七元的1-氧杂-2-氧化锆环庚3,4-二烯中间体，而2,5-二甲硅烷基-1-氧化锆环戊2,3-二烯1b-c与异氰酸酯的反应形成了五元的1-oxa-2-zirconacyclopent-3-ene中间体。这些中间体的其他C–C键形成反应是通过过渡金属化成铜盐，然后添加烯丙基卤提供的烯丙基化产物。