Intramolecular cycloisomerization of a propanes via NHC palladium-catalyzed cascade C-C bond cleavage/C-H activation/C-C bond formation

摘要

A well-defined N-heterocyclic carbene (NHC) palladium-catalyzed intramolecular cyclization reaction of aryl-substituted alkylidenecyclopropanes (ACP) to 1-aryl dihydronaphthalenes is described. The NHC salts were found to suppress beta-hydride elimination from the homoallylpalladium intermediate, which may lead to unwanted alkene formation. A plausible mechanism for the cycloisomerization was proposed.