Ni-Catalyzed Diastereoconvergent Intramolecular Alkene–Aldehyde Reductive Coupling: A Route to <i>syn</i>-Chromanols
Sudipta Kumar Ghosh, Arnab Rooj, Rajesh Chakrabortty, Venkataraman Ganesh
Abstract
We demonstrate for the first time a nickel-catalyzed diastereoconvergent reductive coupling of a heteroatom-attached allyl moiety with aldehydes, viz., O -allyl, O -cinnamyl salicylaldehydes, and others, to afford syn -chromanols exclusively. The reaction proceeds through a [2 + 2 + 1] oxidative cycloaddition involving the active catalyst. This method is applicable to both terminal and internal olefin substrates. The formal syntheses of CP-199.330, CP-199.331, and CP-85.958 have been demonstrated. Control experiments, mass spectrometric analysis, and DFT studies supported the plausible mechanism and the origin of exclusive syn -selectivity.
Topics & Concepts
ChemistryIntramolecular forceAlkeneAldehydeCatalysisCoupling (piping)Combinatorial chemistryMedicinal chemistryStereochemistryOrganic chemistryMechanical engineeringEngineeringCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and CatalysisCatalytic Cross-Coupling Reactions