Photoinduced decarbonylative borylation of alkyl aldehydes through 4-alkyl-1,4-dihydropyridines†
Abstract
We propose a novel approach for the facile decarbonylative borylation of aliphatic aldehydes. In this strategy, 1,4-dihydropyridines (DHPs) are synthesized in a single step from the corresponding aldehydes and subsequently reacted with bis(catecholato)diboron to form an alkyl C–B bond through a photoinduced process. Remarkably, this reaction can be conducted under mild conditions and demonstrates compatibility with a wide range of substrates. The experimental findings, in conjunction with density functional theory (DFT) calculations, reveal the involvement of an electron transfer process between the photocatalyst and DHPs. Notably, the appropriate redox properties of DHPs facilitate the generation of alkyl radicals under these conditions, eliminating the need for any external oxidant.