Synthesis of Amino Acids by Base-Enhanced Photoredox Decarboxylative Alkylation of Aldimines
Jiancheng Wang, Ziyan Shao, Kai Tan, Rui Tang, Qingli Zhou, Min Xu, Ya‐Min Li, Yuehai Shen
Abstract
-hydroxyphthalimide esters with aldimines is reported for synthesizing α-amino esters. A broad scope of alkyl radicals generated under visible light irradiation adds to glyoxylate aldimines in reliably good to excellent yields. Adding inorganic bases such as potassium carbonate significantly enhanced the yields by suppressing the umpolung side reaction. The computation study suggests that the base facilitates hydrogen atom transfer from the radical cation of Hantzsch ester to the N-centered radical intermediates. Introducing amino acid side chains into natural products and drug molecules by this method is demonstrated.
Topics & Concepts
ChemistryAldimineAlkylationUmpolungBase (topology)Organic chemistryAmino acidHydrogen atomAlkylRadicalCatalysisMathematicsNucleophileBiochemistryMathematical analysisRadical Photochemical ReactionsCatalytic C–H Functionalization MethodsSulfur-Based Synthesis Techniques