Synthesis of Heterocycles via Radical Carbonylation

Abstract

Alkyl, aryl, and alkenyl radicals react with CO to form the corresponding acyl radicals, which serve as key intermediates for the synthesis of a wide variety of carbonyl compounds. This chapter focuses on the applications of radical carbonylation for the synthesis of heterocyclic compounds. Radical carbonylation process is reliable for alkyl substrates, since alkyl radicals are sufficiently stable to isomerization unlike rather instable alkyl Pd species. Acyl radicals, key intermediates in the radical carbonylation, have both nucleophilic and electrophilic characters, depending on the attacking reagents and the electrophilic nature is particularly useful to achieve synthesis of nitrogen-containing heterocycles by the reactions with imines, amines, azides, and amidines.