RhIII-Catalyzed Regioselective Preparation of 3-Hetero-Substituted Isocoumarins from Aryl Carboxylic Acids and Alkynes

Article abstract of DOI:10.1002/ejoc.201601330

An oxygen-mediated annulation reaction has been reported herein. Various 3-hetero-substituted isocoumarins were successfully prepared with high efficiency (yields up to 88 %) and good functional-group tolerance (35 examples) in the presence of a rhodium catalyst. A plausible mechanism has also been proposed that shows the high regioselectivity mostly likely originates from the electron-density difference between the alkynyl carbon atoms of the substrate.