Stabilized Ru[(H2O)6]3+ in Confined Spaces (MOFs and Zeolites) Catalyzes the Imination of Primary Alcohols under Atmospheric Conditions with Wide Scope

Imines are ubiquitous intermediates in organic synthesis, and the metal-mediated imination of alcohols is one of the most direct and simple methods for their synthesis. However, reported protocols lack compatibility with many other functional groups since basic supports/media, pure oxygen atmospheres, and/or released hydrogen gas are required during reaction. Here we show that, in contrast to previous metal-catalyzed methods, hexa-aqueous Ru(III) catalyzes the imination of primary alcohols with very wide functional group tolerance, at slightly acid pH and under low oxygen atmospheres. The inorganic metal complex can be supported and stabilized, integrally, within either faujasite-type zeolites (Y and X) or a metal organic framework (MOF), to give a reusable heterogeneous catalyst which provides an industrially viable process well below the flammability limit of alcohols and amines.This work was supported by the MINECO (Spain) (Projects CTQ2017-86735-P, CTQ2016-75671-P, CTQ2014-56312-P, CTQ2014-55178-R, and MAT2013-40823-R and Excellence Units “Severo Ochoa” SEV2016-0683 and “Maria de Maeztu” and MDM-2015-0538) and the European Union through ERC-AdG-2014-671093 (SynCatMatch) and the Ministero dell’Istruzione, dell’Università e della Ricerca (Italy) (FFABR 2017). M.M. thanks the MINECO for a predoctoral contract. R.A. thanks UPV for a postdoctoral contract. J.F.-S. acknowledges financial support from the Subprograma Atracció de Talent – Contractes Postdoctorals de la Universitat de Valencia. We also acknowledge SOLEIL for provision of the synchrotron radiation facility and thank Pierre Fertey for his assistance