Juan A: Casares

Juan A. Casares was born in 1961 in LeĂłn (Spain) and studied chemistry at the Universidad de Valladolid. He obtained his Ph.D. in 1992 under the supervision of Prof. Pablo Espinet, and in 1995 moved to ISSECC (CNR) in Florence, Italy, for a postdoctoral stay. In 1996 he joined the Faculty of Science of the University of Valladolid, where he is Professor since 1997 and Full Professor since 2012. His research studies include dynamic NMR spectroscopy of square-planar complexes and about catalysis of hydrogenation, silylformylation of alkynes, polymerization, and cross-coupling reactions. Currently his research is focused on the study of multimetallic catalytic systems involving 3d metals.

Research topics:

Study of reaction mechanisms of reactions catalyzed by transition metals, in particular palladium  and copper catalyzed cross-coupling reaction.

Development of new multimetallic catalytic systems.


Tlfno:+34    983 184 623  or  983 185 808
Área de Química Inorgånica
Facultad de Ciencias, Universidad de Valladolid
Paseo de BelĂ©n nÂș 7 47011 Valladolid

Recent papers:

Ponce de LeĂłn, Jaime; Marcos-Ayuso, Guillermo; Casares, Juan A.; Espinet, Pablo

“Pd/Cu bimetallic catalysis to access highly fluorinated biaryls from aryl halides and fluorinated arenes”

DOI: 10.1039/D2CC00141A

Marcos-Ayuso, Guillermo; LledĂČs, A.; Casares, Juan A.

Copper(I) activation of C–X bonds: bimolecular vs. unimolecular reaction mechanism

Chem. Commun., 2022.

DOI: 10.1039/D1CC07027D

Lozano-Lavilla, Olmo; GĂłmez-Orellana, Pablo; LledĂłs, AgustĂ­; Casares, Juan A.

Transmetalation Reactions Triggered by Electron Transfer between Organocopper Complexes

Inorg. Chem., 2021, 60, 11633-11639

DOI: 10.1021/acs.inorgchem.1c01595

Carrasco, Desiré; Casares, Juan A.

“Experimental study of the [ZnCl2(THF)2] catalyzed cis/trans-isomerization of [Pd(C6Cl2F3)Me(PPh3)2] and of the transmetalation of trans-[PdCl(C6Cl2F3)(PPh3)2] with [ZnMeCl(THF)2]”.

Inorg. Chim. Acta, 2021, 517, 120206. Homage to Prof. Maurizio Peruzzini

Villar, Pedro, PĂ©rez-Temprano, MĂłnica H.

; Casares, Juan A. ;Álvarez, Rosana ; Espinet P.

Experimental and DFT Study of the [AuAr(AsPh3)] Catalyzed cis/trans Isomerization of [PdAr2(AsPh3)2] (Ar = C6F5 or C6Cl2F3): Alternative Mechanisms and Its Switch upon Pt for Pd Substitution.
Organometallics 2020, 39, 2295–2303 DOI: 10.1021/acs.organomet.0c00245

M. PĂ©rez-Iglesias, R. Infante, J. A. Casares, P. Espinet.

Intriguing Behavior of an Apparently Simple Coupling Promoter Ligand, PPh2(p-C6H4–C6F5), in Their Pd Complexes. Organometallics 2019 DOI: 10.1021/acs.organomet.9b00460

MarĂ­a PĂ©rez-Iglesias, Olmo Lozano-Lavilla, Juan A. Casares
[Cu(C6Cl2F2)(tht)]4: An Extremely Efficient Catalyst for the Aryl Scrambling between Palladium Complexes
Organometallics, 2019, 38, 739–742. DOI: 10.1021/acs.organomet.8b00885

MarĂ­a PĂ©rez-Iglesias, Pablo Espinet, Juan A. Casares
Comparing Protonolysis and Transmetalation Reactions: Microcalorimetric Studies of C–AuI Bonds in [AuRL] Complexes
Inorg. Chem., 201857 (17), pp 11193–11200. DOI: 10.1021/acs.inorgchem.8b01758.

Juan del Pozo, María Pérez-Iglesias, Rosana Álvarez, Agustí Lledós, Juan A. Casares, Pablo Espinet.
“Speciation of ZnMe2, ZnMeCl, and ZnCl2 in Tetrahydrofuran (THF), and Its Influence on Mechanism Calculations of Catalytic Processes” ACS Catal., 2017, 7, 3575–3583
DOI: 10.1021/acscatal.6b03636.

Juan del Pozo, Gorka Salas, Rosana Álvarez, Juan A. Casares, Pablo Espinet
“The Negishi Catalysis: Full Study of the Complications in the Transmetalation Step and Consequences for the Coupling Products”
Organometallics201635, 3604–3611. DOI: 10.1021/acs.organomet.6b00660

Desirée Carrasco, Maximiliano García-Melchor, Juan A Casares, Pablo Espinet
“Dramatic Mechanistic Switch in Sn/AuI Group Exchanges: Transmetalation vs. Oxidative Addition”
Chem. Commun., 2016, 52, 4305-4308.DOI: 10.1039/C5CC10496C

Juan delPozo, Juan A. Casares, Pablo Espinet
“In Situ Generation of ArCu from CuF2 Makes Coupling of Bulky Aryl Silanes Feasible and Highly Efficient”
Chemistry: A European Journal, 2016, 22,4274–4284.
DOI: 10.1002/chem.201504435

Desirée Carrasco, Maximiliano García-Melchor, Juan A Casares, Pablo Espinet
“Dramatic Mechanistic Switch in Sn/AuI Group Exchanges: Transmetalation vs. Oxidative Addition”
Chem. Commun., 2016
DOI: 10.1039/C5CC10496C
delPozo, J; Gioria, E.; Casares, J. A.; Álvarez, R.; Espinet P.
“Organometallic Nucleophiles and Pd: What Makes ZnMe2 Different? Is Au Like Zn?”
Organometallics, 2015, 34, 3120–3128.
DOI: 10.1021/acs.organomet.5b00329

Ana C. Albeniz, Juan A. Casares
“Palladium-Mediated Organofluorine Chemistry” (Review)
Adv. Organomet. Chem. 201462, 1–110.

M. Calvillo-Barahona, J. A. Casares, C. Cordovilla, M. N. Genov, J. M. MartĂ­nez-Ilarduya, P. Espinet
“Diamine-Catalyzed Addition of ZnEt2 to PhC(O)CF3: Two Mechanisms and Autocatalytic Asymmetric Enhancement”
Chem. Eur. J. 2014 DOI: 10.1002/chem.201403648

D. Carrasco, M. H. PĂ©rez-Temprano, J. A. Casares, P. Espinet.
“Cross Alkyl–Aryl versus Homo Aryl–Aryl Coupling in Palladium-Catalyzed Coupling of Alkyl–Gold(I) and Aryl–Halide”
Organometallics2014, Article ASAP. DOI: 10.1021/om500446x

J. delPozo, J. A. Casares, P. Espinet
“Decisive role of Ligand Metathesis in Au/Pd Bimetallic Catalysis”
<a href=” 10.1039/C3CC43133A”>Chem. Commun. 2013, DOI: 10.1039/C3CC43133A

J. delPozo, D. Carrasco, M. H. PĂ©rez-Temprano, M. GarcĂ­a-Melchor, R. Álvarez,  J. A. Casares, P. Espinet
“Stille Coupling Involving Bulky Groups Feasible with Gold Cocatalyst”
Angew. Chem. Int. Ed. 2013, 52, 2189–2193. DOI:  10.1002/anie.201209262

PĂ©rez-Temprano, M. H.; Casares, J. A.; de Lera, A. R.; Álvarez, R.; Espinet, P.
“Strong Metallophilic Interactions in the Palladium Arylation by Gold Aryls”
Angew. Chem. Int. Ed.  201220, 4917–4920

PĂ©rez-Temprano, M. H.; Casares, J. A.; Espinet, P.
“Bimetallic Catalysis using Transition and Group 11 Metals: An Emerging Tool for CC Coupling and Other Reactions”
Chem. Eur. J. 201218, 1864 – 1884.

Garcia-Melchor, M.; Fuentes B., LledĂłs, A.; Casares, J. A.; Ujaque, G.; Espinet, P.
“Cationic Intermediates in the Pd-Catalyzed Negishi Coupling. Kinetic and Density Functional Theory Study of Alternative Transmetalation Pathways in the Me-Me Coupling of ZnMe2 and trans-[PdMeCl(PMePh2)2]“.
J. Am. Chem. Soc2011, 133, 13519–13526.

PĂ©rez-Temprano, M. H.; Gallego, A. M.; Casares, J. A.; Espinet, P.
“Stille Coupling of Alkynyl Stannane and Aryl Iodide, a Many-Pathways Reaction: The Importance of Isomerization.”
Organometallics201130, 611-617.

Fuentes B.; Garcia-Melchor, M.; LledĂłs, A.; Maseras, F.; Casares, J. A.; Ujaque, G.; Espinet. P.
“Palladium Round Trip in the Negishi Coupling of trans- [PdMeCl(PMePh2)2] with ZnMeCl. An Experimental and DFT Study of the Transmetallation Step.”
Chem. Eur. J., 201016, 8596-8599.

Salas, G.; Casares, J. A.; Espinet, P.
“Enthalpy of Ligand Substitution in cis Organopalladium Complexes with Monodentate Ligands.”
Dalton Trans2009, 39, 8413-8420.

Carrera, N.; Pérez-Temprano, M.H.; Albéniz, A. C.; Casares, J. A.; Espinet, P.
”A Convenient Quick Synthesis of SnBu2RCl Derivatives.”
Organometallics2009, 28, 3957-3958.

Martín Pérez-Rodríguez, Ataualpa A. C. Braga, Max Garcia-Melchor, Mónica H. Pérez-Temprano, Juan A. Casares, Gregori Ujaque, Angel R. de Lera, Rosana Álvarez, Feliu Maseras, Pablo Espinet.
“The C-C Reductive Elimination in Palladium Complexes, and the Role of Coupling Additives. A DFT Study Supported by Experiment.”
J. Am. Chem. Soc2009131, 3650-3657

MĂłnica H. PĂ©rez-Temprano, Ainara Nova, Juan A. Casares, Pablo Espinet.
“Observation of a hidden intermediate in the Stille reaction. Study of the reversal of the transmetalation step.”
J Am. Chem. Soc. 2008130,32, 10518-10519.