Copper-Catalyzed Diastereo- and Enantioselective Decarboxylative [3 + 2] Cyclization of Alkyne-Substituted Cyclic Carbamates with Azlactones: Access to γ-Butyrolactams Bearing Two Vicinal Tetrasubstituted Carbon Stereocenters
Ting Wang, Yong You, Zhen‐Hua Wang, Jian‐Qiang Zhao, Yanping Zhang, Jun‐Qing Yin, Ming‐Qiang Zhou, Bao‐Dong Cui, Wei‐Cheng Yuan
Abstract
A copper-catalyzed diastereo- and enantioselective decarboxylative [3 + 2] cyclization reaction of alkyne-substituted cyclic carbamates with azlactones has been established. A range of optically pure γ-butyrolactams bearing two vicinal tetrasubstituted carbon stereocenters were obtained in high yields with good to excellent stereoselectivities (up to 99% yield, 99:1 dr, and 99% ee). This is the first example of asymmetric synthesis γ-butyrolactams containing sterically congested vicinal tetrasubstituted stereocenters via a decarboxylative cyclization pathway.
Topics & Concepts
StereocenterVicinalEnantioselective synthesisChemistryAlkyneYield (engineering)Steric effectsCatalysisStereochemistryCombinatorial chemistryOrganic chemistryMaterials scienceMetallurgyAsymmetric Synthesis and CatalysisCatalytic C–H Functionalization MethodsCatalytic Alkyne Reactions