Visible-light-induced Iodine Anion Catalyzed Decarboxylative Alkenylation

The construction of carbon-carbon bonds and carbon-heterobonds has always been a common concern in the field of organic synthetic chemistry.Carboxylic acids are cheap,abundant and easy to obtain.They are very suitable as synthetic raw materials in the formation of complex molecular frameworks,so people pay attention to decarboxylation coupling.The decarboxylative coupling reaction catalyzed by traditional transition metal has harsh conditions.For example,the temperature is relatively high,which is prone to danger,and the transition metals used are mostly precious metals,which are expensive.Therefore,it is very necessary to develop new catalytic systems to solve these problems.The visible light catalytic system has mild conditions,high reaction efficiency,green and safe,which provides new opportunities for the development of decarboxylation coupling.In the first chapter review of this article,a brief overview of the research progress of decarboxylation coupling reactions under visible light conditions,including the construction of carbon-carbon bonds,carbon-nitrogen bonds,carbon-oxygen bonds,carbon-sulfur bonds and other carbon-heterobonds,further It shows that the catalytic system has high application value.At the same time,the decarboxylation coupling reaction system also tends to use cheap and easily available non-metals instead of metal catalysts.In the second chapter of this article,Our research group have developed an efficient photocatalytic dual decarboxylative alkenylation of α,β-unsaturated carboxylic acids and alkyl N-hydroxyphthalimide(NHP)esters mediated by triphenylphosphine and sodium iodide.This protocol proceeds under 456-nanometer irradiation by visible blue light in the absence of transition metals or organic dye based photoredox catalysts.The reaction is successfully applied to a wide range of redox-active esters derived from aliphatic carboxylic acids(1°,2° and 3°)and α-amino acids,enabling transformations of diverseα,β-unsaturated carboxylic acids to α,β-alkylated styrenes with high efficiency and excellent selectivity under mild conditions.