Efficient Aqueous Intramolecular Alkyne Hydrofunctionalization Catalyzed by Monodentate Gold(I) Complex of Cocarboxylase

ABSTRACT Thiamine diphosphate (ThDP), or cocarboxylase, is an enzyme cofactor that catalyzes crucial metabolic reactions via a thiazolium carbene in all living systems. In this study, we successfully exploit this N ‐heterocyclic carbene ligand for the efficient synthesis of a monodentate gold (I) complex. The resulting ThDP = AuCl complex efficiently catalyzes intramolecular hydroamination, hydroalkoxylation, and hydrocarboxylation of a diverse array of alkyne substrates in water and open air at mild temperatures. This new metal catalyst is environmentally friendly and holds promise for the construction of novel artificial metalloenzymes.