By Irene Hsiao
Professor Guangbin Dong and his lab have discovered a method for opening C-C bonds in aryl-substituted cyclopentanones to produce α-tetralones using a rhodium precatalyst, an N-heterocyclic carbene ligand, and an amino-pyridine co-catalyst, as reported in their recent Nature paper, “Catalytic Activation of Carbon-Carbon Bonds in Cyclopentanones.” While investigating a reaction to couple ketones with olefins, Dong and postdoc Ying Xia noticed a small amount of α-tetralone formed as byproducts. Determined to optimize the formation of the α-tetralone product, a common intermediate in organic synthesis, they discovered that a metal could insert between the first two carbons on an unstrained ring when an aryl group was present on the third. After activating a C-H bond on the aromatic ring, reductive elimination results in the α-tetralone. Dong and his group have shown that the same strategy can also turn aryl-substituted cyclohexanones into α-indanones.