Enabling Reductive C–N Cross-Coupling of Nitroalkanes and Boronic Acids by Steric Design of P(III)/P(V)═O Catalysts
Gen Li, Yuzuru Kanda, Seung Youn Hong, Alexander T. Radosevich
Abstract
An organophosphorus-catalyzed C–N bond-forming reductive coupling of nitroalkanes with arylboronic acids and esters is reported. The method shows excellent chemoselectivity for the nitro/boronic acid substrate pair, allowing the synthesis of N-(hetero)arylamines rich in functionalization. The identification of a sterically reduced phosphetane catalyst capable of productive coupling in the P(III)/P(V)═O redox manifold is the key enabling development. Combined experimental kinetics and computational mechanistic studies show that the sterically reduced catalyst affects post-rate-limiting steps to enable the C–N coupling event in preference to deleterious side-paths.
Topics & Concepts
ChemistrySteric effectsCatalysisChemoselectivityBoronic acidSubstrate (aquarium)Combinatorial chemistryNitroLimitingCoupling (piping)StereochemistryOrganic chemistryGeologyAlkylMechanical engineeringEngineeringOceanographyCatalytic Cross-Coupling ReactionsAsymmetric Hydrogenation and CatalysisCatalytic C–H Functionalization Methods