Article
Chemistry, Physical
Jessica Rodriguez, David Vesseur, Alexis Tabey, Sonia Mallet-Ladeira, Karinne Miqueu, Didier Bourissou
Summary: A (MeDalphos)AuCI complex has been discovered to efficiently catalyze the cross-coupling reaction of indoles and allyl acetates/alcohols. The reaction tolerates various functional groups and selectively produces branched C3-allylated products. It utilizes the hemilabile character of the P<^>N ligand.
Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Wei Sun, Rui-Rui Li, Gui-Xiu Tian, Xiao-Chen Wang
Summary: A borane/gold(I) co-catalytic system was designed and applied in C-H functionalization reactions and cycloaddition reactions between tertiary amines and alpha-alkynylenones, efficiently introducing a furan ring into the amine molecule.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Dominik Birnthaler, Rok Narobe, Eliseo Lopez-Berguno, Christoph Haag, Burkhard Koenig
Summary: Ligand-to-metal charge transfer (LMCT) photo-catalysis enables the activation and utilization of halides and other heteroatoms in metal complexes. The application of bismuth LMCT in organic radical coupling reactions has been expanded, generating chlorine and carboxyl radicals in net-oxidative and redox-neutral photochemical reactions. The study reveals BiCl4- and BiCl52- as the catalytically active bismuth species under 385 nm irradiation, providing insight into the reactivity of the highly reactive bismuth(II) catalyst fragment through cyclic voltammetry and UV-vis studies.
Review
Chemistry, Multidisciplinary
Sergio Gonzalez-Granda, Jesus Albarran-Velo, Ivan Lavandera, Vicente Gotor-Fernandez
Summary: The combination of metal-, photo-, enzyme-, and/or organocatalysis is a versatile approach in synthetic chemistry, particularly for the creation of chiral centers. This review focuses on the recent developments in the simultaneous use of enzymes and transition metal catalysts, as well as the integration of multiple bioprocesses and metal-catalyzed transformations in linear cascades. Challenges such as catalyst compatibility, reaction media, and cross-reactivities are addressed by strategies such as catalyst coimmobilization, compartmentalization, and flow chemistry. The review also highlights the application of bionanohybrid materials, where enzymes and metals are coimmobilized on suitable supports.
Article
Chemistry, Multidisciplinary
Illia Lenko, Alexander Mamontov, Carole Alayrac, Remi Legay, Bernhard Witulski
Summary: The research demonstrates the divergent Pd-catalyzed reaction cascades with various 1,3-diynamides, leading to different products depending on the presence or absence of TBAF. Furthermore, deuterium labeling experiments reveal the unique formation mechanism of the products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Luo-Rong Yuan, Shun-Jun Ji, Xiao-Ping Xu
Summary: In this study, a cobalt-catalyzed coupling-cyclization cascade reaction was investigated, which allowed for the synthesis of various spiroindoline compounds by modifying substituents at the N1- and C2-positions in the indole skeleton. Interestingly, the spiroindoline products could undergo despirocyclization in the presence of amines, enabling efficient construction of enamine compounds.
Article
Chemistry, Applied
Miguel A. Munoz-Torres, Fernando Martinez-Lara, Marta Solas, Samuel Suarez-Pantiga, Roberto Sanz
Summary: The combination of organolithium chemistry with gold catalysis offers a new synthetic strategy for accessing polysubstituted indoles and carbazoles. This method utilizes ketopyrroles as starting materials and involves a series of reactions to selectively synthesize the desired products.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Fernando Martinez-Lara, Anisley Suarez, Noelia Velasco, Samuel Suarez-Pantiga, Roberto Sanz
Summary: The gold-catalyzed transformation of propargylic glycols with thiols results in the formation of alpha-indol-3-yl alpha-((Z)-2-thioalkenyl) ketones through a complex but selective reaction mechanism. This sequence involves regioselective thiolation of indolyl diols followed by the attack of sulfur on the activated alkyne, rather than the indole. The final compounds are obtained in high yields from simple starting materials such as indolyl acyloins, ethynyl magnesium bromide, and thiols.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Yunxiao Zhang, Yunhong Niu, Youyuan Guo, Jiaxin Wang, Yizhi Zhang, Shanshan Liu, Xiao Shen
Summary: In this study, photocatalyzed cascade reactions between readily available cyclopropanols and alpha-trifluoromethyl-substituted olefins were reported for the synthesis of fused gem-difluorooxetanes. Two rings and three bonds were efficiently constructed in one reaction. The reaction demonstrated broad substrate scope and the downstream transformations of the products highlighted the synthetic potential. Mechanistic study supported the presence of cascade photoredox catalysis and energy transfer catalysis/direct photo-excitation processes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Multidisciplinary
T. Ghosh, S. Bhakta
Summary: This review summarizes recent developments (from 2006 to 2022) in the synthesis of important and efficient carbo- and heterocycles using gold-catalyzed cascade protocols. The methodologies discussed in this paper involve controlling selectivity, cost-effectiveness, and ease of product formation through the ligand, counter anion, catalyst, substrate, and reaction conditions. Gold-catalyzed cascade reactions encompass different strategies, including cyclization, hydroarylation, intermolecular and intramolecular cascade reactions, and more. This type of reaction is valuable for the synthesis of spiro, fused, bridged carbo- and heterocycles.
Review
Acoustics
Ingrid V. Machado, Jhonathan R. N. dos Santos, Marcelo A. P. Januario, Arlene G. Correa
Summary: By utilizing ultrasound-assisted multicomponent reactions under heterogeneous catalysis, it is possible to efficiently synthesize biologically active organic compounds with reduced costs and energy consumption.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Chemistry, Organic
Antonia Rinaldi, Vittoria Lange, Dina Scarpi, Ernesto G. Occhiato
Summary: In this study, the synthesis of (+/-)-epi-jungianol was successfully achieved through a gold(I)-catalyzed propargyl Claisen rearrangement/hydroarylation cascade reaction of suitably substituted propargyl vinyl ethers. Two different routes were compared, with the one involving substrates with less substitution on the vinyl moiety providing a higher overall yield despite requiring two additional steps. Additionally, a method for preparing acid-sensitive propargyl vinyl ethers with an alpha-alkyl-substituted vinyl moiety and their reactivity under gold catalysis was reported.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Cristian Cavedon, Sebastian Gisbertz, Susanne Reischauer, Sarah Vogl, Eric Sperlich, John H. Burke, Rachel F. Wallick, Stefanie Schrottke, Wei-Hsin Hsu, Lucia Anghileri, Yannik Pfeifer, Noah Richter, Christian Teutloff, Henrike Mueller-Werkmeister, Dario Cambie, Peter H. Seeberger, Josh Vura-Weis, Renske M. van der Veen, Arne Thomas, Bartholomaus Pieber
Summary: We demonstrate visible-light-mediated carbon-heteroatom cross-coupling reactions using a photoactive Ni(II) precatalyst. The activation of this precatalyst involves an initial intraligand charge transfer event triggered by visible light irradiation. Additionally, a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-coupling reactions is obtained through ligand polymerization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
David M. Upp, Rui Huang, Ying Li, Max J. Bultman, Benoit Roux, Jared C. Lewis
Summary: Artificial metalloenzymes (ArMs) were engineered to catalyze diazo cross-coupling resulting in high enantioselectivity alkene reduction to alkane in a one-pot cascade reaction. Directed evolution improved reaction yields and selectivities for various substrates. Molecular dynamics simulations of ArM variants were used to understand the structural role of the cofactor on ArM conformational dynamics, highlighting the ability of ArMs to control both catalyst stereoselectivity and chemoselectivity in complex media.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Tingrui Li, Yilitabaier Julaiti, Xiaopeng Wu, Jie Han, Jin Xie
Summary: The gold-catalyzed ring-opening rearrangement of cyclopropenes provides an efficient method for synthesizing polysubstituted naphthols or aryl-substituted furans. The reaction selectivity between naphthols and furans can be switched by using different gold-carbenes or gold-carbocations as catalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Paul Zaby, Jan Blasius, Anna K. Mueller, Steven P. Nolan, Oldamur Holloczki
Summary: The formation mechanism of metal-N-heterocyclic carbene (NHC) complexes from imidazolium salts in the presence of weak bases was investigated through theoretical methods. Quantum chemical calculations revealed that both sodium acetate and trimethylamine facilitate complex formation. Molecular dynamics simulations showed that the ionic nature of the [AuCl2](-) and imidazolium ions, as well as the sodium acetate base, keep these species associated in the reaction mixture through ion pairing. The neutral amine, however, remains mostly separated from the other reaction partners, making it a significantly less effective base.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Xinyuan Ma, Manoj V. Mane, Luigi Cavallo, Steven P. Nolan
Summary: An efficient method for the regioselective 1,2-hydrosilylation of N-heteroarenes using silanes as hydride donors is described. The versatile catalyst [RuCl(PPh3)(2)(eta(5)-(3-phenylindenylidene))] is employed for the first time in this catalytic reaction, displaying high efficiency at low loading and mild conditions. The mechanism of this transformation is investigated through stoichiometric reactions and DFT calculations.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Leonardo Andreoni, Giovanni Mariano Beneventi, Gabriele Giovanardi, Gianpiero Cera, Alberto Credi, Arturo Arduini, Andrea Secchi, Serena Silvi
Summary: We synthesized and characterized a dansyl calix[6]arene derivative and its pseudorotaxane complex, and found that it has remarkable complexation ability. The dansyl moieties in the derivative can signal the state of the system through fluorescence, be reversibly protonated to modulate the complexation abilities, and participate in photoinduced electron transfer processes to tune the stability of the complex.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Sebastien G. Guillet, Aleksei A. Logvinov, Vladislav A. Voloshkin, Ekaterina A. Martynova, Steven P. Nolan
Summary: Researchers report a simple method for the synthesis of azetidines from 2-isoxasoline-3-carboxylates and alkenes, using [Au(cbz)(NHC)] complexes as photocatalysts. The reaction is applicable to a wide range of substrates. Mechanistic studies confirm the energy transfer pathway. This study further expands the potential application of gold catalysts in energy transfer chemistry and catalysis.
Article
Chemistry, Physical
David C. Cabanero, Jennifer A. Nguyen, Catherine S. J. Cazin, Steven P. Nolan, Tomislav Rovis
Summary: A system has been developed that uses deep red to near-infrared light to activate a latent ruthenium olefin metathesis catalyst. This is achieved by using an osmium(II) photocatalyst that is excited to its triplet state and a latent solvent-coordinated, cationic precatalyst that undergoes excited-state single-electron reduction. The system demonstrates excellent spatiotemporal control under light irradiation and shows improved light penetration through barriers.
Article
Chemistry, Physical
Nikolaos V. Tzouras, Leandros P. Zorba, Entzy Kaplanai, Nikolaos Tsoureas, David J. Nelson, Steven P. Nolan, Georgios C. Vougioukalakis
Summary: Despite the usefulness of gold catalysis in organic synthesis, it often requires activators and/or additives to generate cationic forms of gold catalysts. In this study, hexafluoroisopropanol (HFIP) is found to be a simple tool for gold-catalyzed cycloisomerizations, eliminating the need for external activators. HFIP acts as both a solvent and an activator through dynamic activation of the Au-Cl bond via hydrogen bonding. This unique mode of catalysis enables efficient and scalable cyclization reactions without the use of complex ligand/catalyst designs or activators.
Article
Chemistry, Physical
Sylwia Ostrowska, Lorenzo Palio, Agnieszka Czapik, Subhrajyoti Bhandary, Marcin Kwit, Kristof Van Hecke, Steven P. Nolan
Summary: In this study, a synthetic protocol was developed to prepare palladacycle complexes using a mild base and environmentally friendly solvent, with a focus on complexes with backbone-substituted N-heterocyclic carbene ligands. The accessible complexes exhibited high catalytic activity in the Buchwald-Hartwig amination, with low catalyst loading and mild reaction conditions achieved in a green solvent.
Article
Chemistry, Organic
Shiyi Yang, Xiang Yu, Yaxu Liu, Michele Tomasini, Lucia Caporaso, Albert Poater, Luigi Cavallo, Catherine S. J. Cazin, Steven P. Nolan, Michal Szostak
Summary: The Suzuki-Miyaura cross-coupling reaction enables the construction of biaryl ketones from inert amide bonds. However, the mechanism of C(acyl)-N bond oxidative addition and catalyst effect in this reaction remain poorly understood. This study investigates the use of [Pd(NHC)(sulfide)Cl-2] catalysts for amide N-C bond activation and presents the reaction development, kinetic studies, and reaction scope. DFT studies were also conducted to gain insight into the mechanism of C(acyl)-N bond oxidative addition and catalyst activation. The results suggest that [Pd(NHC)(sulfide)Cl-2] precatalysts could find application in C(acyl)-X bond activation in organic synthesis and catalysis.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Xinyuan Ma, Steven P. Nolan
Summary: The first-generation ruthenium-indenylidene olefin metathesis complex catalyzes the 1,2-hydrosilylation reaction to produce dihydroquinoline derivatives with high regioselectivity. The complex shows excellent catalytic efficiency when the challenging Ph2SiH2 hydride donor is used. The reaction is efficient with low catalyst loadings and applicable to a wide range of quinoline derivatives and N-heterocycles. A proposed mechanism for this transformation is based on stoichiometric reactions.
Article
Chemistry, Inorganic & Nuclear
Thomas Scattolin, Aleksei A. Logvinov, Nikolaos V. Tzouras, Catherine S. J. Cazin, Steven P. Nolan
Summary: N-heterocyclic carbene (NHC) ligands have evolved from being lab curiosities to important supporting ligands in various fields such as organometallic chemistry, homogeneous catalysis, medicinal chemistry, and materials science.
Article
Chemistry, Inorganic & Nuclear
Sofie M. P. Vanden Broeck, Nikolaos V. V. Tzouras, Marina Saab, Kristof Van Hecke, Busra Dereli, Ida Ritacco, Luigi Cavallo, Georgios C. C. Vougioukalakis, Pierre Braunstein, Steven P. P. Nolan, Andreas A. A. Danopoulos, Catherine S. J. Cazin
Summary: The 4-RN-1,3-Ar-2-imidazolium salt, R = iPr, tBu, Ar = Mes, Dipp, underwent metalation by Au-I at the C2-, C5-, and 4-RN positions, depending on the reactants and conditions used. A rare direct rearrangement of the Au-I aminide to an abnormal imidazol-5-ylidene Au-I complex was also observed, which may involve TfO- facilitated H+ transfer, according to a DFT study.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Sylwia Ostrowska, Pierre Arnaut, David J. Liptrot, Catherine S. J. Cazin, Steven P. Nolan
Summary: The synthesis, isolation, and full characterization of a new copper complex [Cu(IPr)(OC(H)(CF3)(2))] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) are reported. This copper(I) complex is a versatile synthon capable of activating various X-H bonds including C-H, N-H, and S-H bonds. [Cu(IPr)(OC(H)(CF3)(2))] was investigated as a pre-catalyst in several catalytic reactions.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Raphael Gauthier, Nikolaos V. Tzouras, Steven P. Nolan, Jean-Francois Paquin
Summary: The gold-catalyzed hydration of 2,2,2-trifluoroethyl-substituted alkynes exhibits high regioselectivity, resulting in the formation of β-trifluoromethylketones as the major products. This transformation highlights the significant directing effect of the trifluoromethyl group, mediated by its inductive effect, in gold-catalyzed addition to alkynes.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Gabriele Giovanardi, Gabriele Scarica, Valentina Pirovano, Andrea Secchi, Gianpiero Cera
Summary: We report the first example of gold(I)-catalyzed intramolecular hydroarylation of alkynes for the direct synthesis of inherently chiral calix[4]arenes. This efficient and atom-economical method allows for a formal meta-functionalization of the calix[4]arene macrocycle, leading to the synthesis of a wide range of N-heterocyclic, chiral compounds with high yields and functional group tolerance.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Leonardo Andreoni, Federica Cester Bonati, Jessica Groppi, Davide Balestri, Gianpiero Cera, Alberto Credi, Andrea Secchi, Serena Silvi
Summary: We synthesized and characterized [2]rotaxanes based on a stilbazolium dye and a calix[6]arene macrocycle. Due to the non-symmetry of both components, two orientational isomers were obtained. The two isomers exhibited distinct photophysical and photochemical properties in solution and solid state, surpassing the unencapsulated dye.
CHEMICAL COMMUNICATIONS
(2023)
