<i>C</i><sub>2</sub>-Symmetric Dinickel Catalysts for Enantioselective [4 + 1]-Cycloadditions
Michael J. Behlen, Christopher Uyeda
Abstract
Dinickel naphthyridine–bis(oxazoline) catalysts promote enantioselective intermolecular [4 + 1]-cycloadditions of vinylidene equivalents and 1,3-dienes. The products of this reaction are methylenecyclopentenes, and the exocyclic alkene is generally obtained with high Z selectivity. E- and Z-dienes react in a stereoconvergent fashion, providing cycloadducts with the same sense of absolute stereochemistry and nearly identical ee values. This feature allows dienes that are commercially available as E/Z mixtures to be used as substrates for the cycloaddition. A DFT model for the origin of asymmetric induction is provided.
Topics & Concepts
ChemistryEnantioselective synthesisOxazolineCycloadditionAlkeneIntermolecular forceCatalysisSelectivityStereochemistryAsymmetric inductionMedicinal chemistryComputational chemistryOrganic chemistryMoleculeCyclopropane Reaction MechanismsAsymmetric Synthesis and CatalysisSynthesis and Catalytic Reactions