%0 Unpublished work %T Reduction of secondary amides to imines catalysed by Schwartz’s reagent %+ Laboratoire de Chimie Moléculaire et de Catalyse pour l'Energie (ex LCCEF) (LCMCE) %A Donnelly, Liam, J. %A Berthet, Jean-Claude %A Cantat, Thibault %8 2022-02-07 %D 2022 %R 10.26434/chemrxiv-2022-bzr64 %Z Chemical Sciences/Catalysis %Z Chemical Sciences/Organic chemistryPreprints, Working Papers, ... %X The partial reduction of amides is a challenging transformation that must overcome the intrinsic stability of the amide bond, a ubiquitous motif in organic chemistry, and exhibit high chemoselective control. To address this challenge, we describe a zirconium-catalysed synthesis of imines by the reductive deoxygenation of secondary amides. This reaction exploits the excellent chemoselectivity of Schwartz’s reagent (Cp$_2$Zr(H)Cl) to avoid overreduction to amine products and utilises (EtO)$_3$SiH as a mild stoichiometric reductant to enable catalyst turnover. The reaction generally proceeds with high yields (13 examples, 70 to 95% yield) and tolerates a variety of functional groups (alkene, ether, nitro, etc.). Stoichiometric mechanistic investigations suggest the regeneration of the active [Zr]–H catalyst is achieved through the σ-bond metathesis of Si–H and Zr–OR. %G English %2 https://cea.hal.science/cea-03571753/document %2 https://cea.hal.science/cea-03571753/file/Donnely_ChemXriv2022.pdf %L cea-03571753 %U https://cea.hal.science/cea-03571753 %~ CEA %~ CNRS %~ OPENAIRE %~ PUBNIMBE %~ INC-CNRS %~ IRAMIS-NIMBE %~ CEA-UPSAY %~ UNIV-PARIS-SACLAY %~ UNIVERSITE-PARIS-SACLAY %~ GS-ENGINEERING %~ IRAMIS %~ GS-CHIMIE %~ GS-PHYSIQUE %~ INSTITUT-SCIENCES-LUMIERE %~ TEST2-HALCNRS