doi:10.1016/j.tetasy.2016.04.006engCarmona, DanielViguri, FernandoAsenjo, AinaraLamata, PilarLahoz, Fernando J.García-Orduña, PilarAsymmetric 1, 3-dipolar cycloaddition reactions between methacrylonitrile and nitrones catalysed by well-defined M(diphosphane) (M=Rh, Ir) complexesART-2016-94931The cationic half-sandwich aqua-complexes (¿ 5-C5Me5)M(PP*)(H2O)]SbF6]2 M=Rh, Ir; PP* =(R)-Benphos, (R)-Cyphos, (2R, 4R)-Norphos] catalyse the 1, 3-dipolar cycloaddition reaction of nitrones with methacrylonitrile with perfect regioselectivity, low-to-perfect endo-selectivity and low-to-moderate enantioselectivity. The active species involved in the catalytic process, (¿ 5-C5Me5)M(PP*)(methacrylonitrile)]SbF6]2, have been isolated and characterised as mixtures of the (S)- and (R)-at-metal epimers. NMR measurements of these mixtures indicated that the (R M)-isomers epimerise to the corresponding (S M) counterparts. The molecular structure of the rhodium complex (S Rh, R C)-(¿ 5-C5Me5)Rh((R)-Benphos)(methacrylonitrile)]SbF6]2 has been determined by X-ray diffraction methods. Diastereomerically pure (S Rh, R C)-(¿ 5-C5Me5)Rh(PP*)(methacrylonitrile)]SbF6]2 compounds catalyse stoichiometrically the above mentioned dipolar cycloaddition reaction with up to 90% enantiomeric excess, thus indicating the influence of the metal handedness on the catalytic stereochemical outcome. Catalysts can be recycled up to three times without a significant loss of either activity or selectivity.2016http://zaguan.unizar.es/record/6159410.1016/j.tetasy.2016.04.006http://zaguan.unizar.es/record/61594oai:zaguan.unizar.es:61594info:eu-repo/grantAgreement/ES/DGA/E63info:eu-repo/grantAgreement/ES/MINECO/Consolider-Ingenio/CSD2006-0015info:eu-repo/grantAgreement/ES/MINECO/CTQ2012-32095info:eu-repo/grantAgreement/ES/MINECO/CTQ2015-66079-PTetrahedron: Asymmetry 27, 11-12 (2016), [26 pp.]by-nc-ndhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccess