Regioselective BF3·Et2O-catalyzed C–H functionalization of indoles and pyrrole with reaction of α-diazophosphonates†
Abstract
Facile regiospecific intermolecular C–H insertion reactions of α-diazophosphonates with indole or pyrrole derivatives catalyzed by trifluoroborane have been developed. The reaction protocol was effective for regioselective C–H insertion depending on the substitution pattern on the indole moiety and carbene migratory model. This represents the first straightforward access to N-unsubstituted β-(3-indol)-β-aminophosphonates and β-(2-pyrrol)-β-aminophosphonates containing quaternary carbon centers in moderate to good yields.