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Braga AAC, Maseras F, Urbano J, Caballero A, Díaz-Requejo MM, Pérez PJ. Mechanism of Alkane C−H Bond Activation by Copper and Silver Homoscorpionate Complexes. Organometallics 2006. [DOI: 10.1021/om060445h] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ataualpa A. C. Braga
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
| | - Juan Urbano
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
| | - Ana Caballero
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
| | - M. Mar Díaz-Requejo
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
| | - Pedro J. Pérez
- Institute of Chemical Research of Catalonia (ICIQ), Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain, and Laboratorio de Catálisis Homogénea, Departamento de Química y Ciencia de los Materiales, Unidad Asociada al CSIC, Universidad de Huelva, Campus de El Carmen, 21007 Huelva, Spain
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Affiliation(s)
- Ataualpa A. C. Braga
- Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Catalonia, Spain, and Unitat de Química Física, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Gregori Ujaque
- Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Catalonia, Spain, and Unitat de Química Física, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ), 43007 Tarragona, Catalonia, Spain, and Unitat de Química Física, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
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García-Cuadrado D, Braga AAC, Maseras F, Echavarren AM. Proton abstraction mechanism for the palladium-catalyzed intramolecular arylation. J Am Chem Soc 2006; 128:1066-7. [PMID: 16433509 DOI: 10.1021/ja056165v] [Citation(s) in RCA: 626] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Under the usual conditions, the Pd-catalyzed arylation does not involve an electrophilic aromatic substitution reaction. On the basis of DFT calculations, we propose a mechanism for the Pd-catalyzed arylation that involves a proton abstraction by a carbonate or related ligand and that provides a satisfactory explanation for the experimental data.
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Braga AAC, Morgon NH, Ujaque G, Maseras F. Computational Characterization of the Role of the Base in the Suzuki−Miyaura Cross-Coupling Reaction. J Am Chem Soc 2005; 127:9298-307. [PMID: 15969613 DOI: 10.1021/ja050583i] [Citation(s) in RCA: 267] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of the base in the transmetalation step of the Suzuki-Miyaura cross-coupling reaction is analyzed computationally by means of DFT calculations with the Becke3LYP functional. The model system studied consists of Pd(CH=CH2)(PH3)2Br as the starting catalyst complex, CH2=CHB(OH)2 as the organoboronic acid, and OH- as the base. The two main mechanistic proposals, consisting of the base attacking first either the palladium complex or the organoboronic acid, are evaluated through geometry optimization of the corresponding intermediates and transition states. Supplementary calculations are carried out on the uncatalyzed reaction and on a process where the starting complex is Pd(CH=CH2)(PH3)2(OH). These calculations, considered together with available experimental data, strongly suggest that the main mechanism of transmetalation in the catalytic cycle starts with the reaction of the base and the organoboronic acid.
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Affiliation(s)
- Ataualpa A C Braga
- Unitat de Química Física, Edifici C.n, Universitat Autonoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
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