A sequential oxidative radical alkoxycarbonylation and aromatization of 2-isocyanobiphenyl with carbazates was developed to furnish phenanthridine-6-carboxylates. Various functional groups such as methoxy, chloro, fluoro, trifluoromethoxy, and trifluoromethyl groups were tolerated well under the reaction conditions. The sequential radical addition-cyclization strategy represents a practical route to access phenanthridine-6-carboxylates.
Metal-free, visible-light-promoted oxidative radical cyclization of <i>N</i>-biarylglycine esters: one-pot construction of phenanthridine-6-carboxylates in water
作者:Palani Natarajan、Deachen Chuskit、Priya Priya
DOI:10.1039/c9gc01557d
日期:——
A metal-free, visible-light (blue LED: hν = 425 ± 15 nm) photoredox-catalyzed intramolecular cyclization reaction of N-biarylglycine esters to phenanthridine-6-carboxylates in water under an open air atmosphere at ambient conditions has been developed. A plausible mechanism is proposed for the reaction. Using a catalytic amount (5 mol%) of rose bengal and a blue LED, the N-biarylglycine esters were