title: Silver(I)-Catalyzed Addition of Phenols to Alkyne Cobalt Cluster Stabilized Carbocations.
abstract: A smooth catalytic method to use phenols as the nucleophilic partner in the Nicholas reaction has been developed. The method uses either Ag(I) or Au(I) catalysts with AgClO4 or AgBF4 as the most efficient catalysts tested. Neither additional additives nor cocatalysts were required and the formation of the corresponding phenol adducts occurred in excellent yields. The process has the single limitation of the inability of less nucleophilic phenols (4-nitrophenol) to generate the corresponding adducts. Additionally, the reaction is highly diastereoselective. DFT calculations allow a catalytic cycle to be proposed that involves trimetallic intermediates; the rate-determining step of the reaction is hydroxy-group elimination in a cobalt-silver trimetallic intermediate.
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense, 28040, Madrid, Spain.|Instituto de Química Orgánica General, Instituto de Química Orgánica, Consejo Superior de Investigaciones Científicas (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain.|Centro de Innovación en Química Avanzada (ORFEO-CINQA).
authors.forename: Carolina
authors.initials: C
authors.lastname: Valderas
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense, 28040, Madrid, Spain.|Centro de Innovación en Química Avanzada (ORFEO-CINQA).
authors.forename: Luis
authors.identifier: http://orcid.org/0000-0002-9054-3118
authors.initials: L
authors.lastname: Casarrubios
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain.|Centro de Innovación en Química Avanzada (ORFEO-CINQA).
authors.forename: Agusti
authors.identifier: http://orcid.org/0000-0001-7909-422X
authors.initials: A
authors.lastname: Lledos
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès, Spain.|Centro de Innovación en Química Avanzada (ORFEO-CINQA).
authors.forename: Manuel A
authors.identifier: http://orcid.org/0000-0002-6175-3941
authors.initials: MA
authors.lastname: Ortuño
authors.affiliation: Instituto de Química Orgánica General, Instituto de Química Orgánica, Consejo Superior de Investigaciones Científicas (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain. mc.delatorre@csic.es.|Centro de Innovación en Química Avanzada (ORFEO-CINQA). mc.delatorre@csic.es.
authors.forename: María C
authors.identifier: http://orcid.org/0000-0002-7310-8202
authors.initials: MC
authors.lastname: de la Torre
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense, 28040, Madrid, Spain. sierraor@ucm.es.|Centro de Innovación en Química Avanzada (ORFEO-CINQA). sierraor@ucm.es.
authors.forename: Miguel A
authors.identifier: http://orcid.org/0000-0002-3360-7795
authors.initials: MA
authors.lastname: Sierra
keywords: Nicholas reaction; density functional calculations; homogeneous catalysis; reaction mechanisms; silver