Facile synthesis of alkylphosphonates from 4-alkyl-1,4-dihydropyridines via photoinduced formal deformylative phosphonylation†
Abstract
Here, an unprecedented formal deformylative phosphonylation is disclosed. Under the catalysis of 1 mol% 1,2,3,5-tetrakis(diphenylamino)-4,6-dicyanobenzene (4DPAIPN) and in the presence of 200 mol% triethylamine as an additive, 4-alkyl-1,4-dihydropyridines (DHPs), derived from aldehydes, smoothly underwent phosphonylation with 9-fluorenyl o-phenylene phosphite, allowing facile synthesis of alkylphosphonates. This strategy is applicable to primary, secondary, and even tertiary DHPs and exhibits a broad substrate scope and excellent functional group tolerance, thereby enabling the late-stage phosphonylation of a series of naturally-occurring bioactive and biorelevant molecules.