Catalytic Reactions of Terminal Alkynes Using Rhodium(I) Complexes Bearing 8‑Quinolinolate Ligands

8-Quinolinolate is a monoanionic, hard, strongly σ-donating ligand that can form strong chelates with various metals. However, studies of the catalytic activities of soft transition metal complexes such as greater than second row, low-valent, late-transition metals having 8-quinolinolate ligands had not been well explored until recently. In recent years, several research groups including our own have studied and developed various reactions of terminal alkynes using rhodium­(I) catalysts containing an 8-quinolinolate ligand. In this Perspective, we surveyed the transformations of terminal alkynes using 8-quinolinolato rhodium­(I) catalyst such as additions of alcohols, amines, and thiols as well as polymerization, trimerization, dimerization, and alkyne/alkene [2 + 2] cycloaddition. Mechanistic studies based on theoretical calculations of hydroalkoxylation of alkynes and alkyne/alkene [2 + 2] cycloaddition reactions have also been described.