Zinc‐Catalyzed Enantioselective [3+2] Cycloaddition of Azomethine Ylides Using Planar Chiral [2.2]Paracyclophane‐Imidazoline N,O‐ligands
Sundaravel Vivek Kumar, Patrick J. Guiry
Abstract
Abstract We present a facile synthetic route toward a novel series of imidazolinyl‐[2.2]paracyclophanol (UCD‐Imphanol) ligands possessing central and planar chirality. Both sets of diastereomeric ligands were successfully purified by column chromatography. The preliminary application of this family of ligands showed excellent activities in the asymmetric Zn‐catalyzed azomethine ylide cycloaddition. Enantioenriched pyrrolidines, in a substrate scope of 20 examples, were accessed in high levels of endo / exo ratios (up to >99/1) and enantioselectivities (up to >99 % ee) with excellent yields (up to 99 %) by using ( S , S , S P )‐UCD‐Imphanol/( S , S , R P )‐UCD‐Imphanol, respectively.
Topics & Concepts
Enantioselective synthesisDiastereomerCycloadditionChemistryCatalysisPlanar chiralityAzomethine ylideSubstrate (aquarium)Chirality (physics)ZincCombinatorial chemistryStereochemistryMedicinal chemistryOrganic chemistry1,3-Dipolar cycloadditionQuarkGeologyOceanographyQuantum mechanicsNambu–Jona-Lasinio modelPhysicsChiral symmetry breakingCarbohydrate Chemistry and SynthesisAsymmetric Synthesis and CatalysisTraditional and Medicinal Uses of Annonaceae