The reactions of alkynes with CO in the presence of transition metal complexes have been attractive since Reppe discovered acrylic acid formation using an acetylene, CO and nickel carbonyl complex. 1 Since then, it has been reported that alkynes can react with CO in the presence of various transition metal complexes. 2 However, the carbonylation of metal–alkyne complexes with CO has not been reported. As shown in eqn. (1), formally a metalacyclobutenone is ...
