BF2-Chelates of N-Acylhydrazones as Versatile Coupling Partners in Photoredox Promoted Reactions

Abstract

Five-membered difluoroboryl chelate complexes are competent substrates for radical reactions with various radical precursors including potassium trifluoroborates, bis(catecholato)siliconates, 4-alkyl-substituted Hantzsch esters, dihydroquinazolinones, esters of N-hydroxyphthalimide, Katritzky salts, alkyl iodides and thiols. Using these reagents, primary, secondary, and tertiary radicals can be generated under oxidative or reductive conditions and add at the C=N bond of the difluoroboryl chelates leading to hydrazide products.