Article
Chemistry, Organic
Riccardo Pedrazzani, Juzeng An, Magda Monari, Marco Bandini
Summary: New chiral BINOL-based phosphate counterions have been synthesized and utilized in the gold-catalyzed enantioselective dearomatization reaction, leading to a range of densely functionalized C1-allylated naphthalenones with high levels of chemo-, regio-, and stereoselectivity (up to 95% ee).
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Nabakumar Bera, Bhabani Sankar Lenka, Burkhard Konig, Debayan Sarkar
Summary: Dearomative spiro-etherification of naphthols was achieved using catalytic amounts of riboflavin tetracetate (RFTA) as a photosensitizer and molecular oxygen as a terminal oxidizing agent under blue light (440 nm) irradiation in the presence of acid. The presence of acid increased the photooxidation power of RFTA and facilitated the dearomatization reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Qing-Xia Zhang, Jia-Hao Xie, Qing Gu, Shu-Li You
Summary: An asymmetric allylic dearomatization reaction of 1-nitro-2-naphthol derivatives with Morita-Baylis-Hillman (MBH) adducts has been developed using a Pd catalyst and Trost ligand (R,R)-L1. The reaction proceeds smoothly in 1,4-dioxane at room temperature, resulting in good yields (up to 92%) and enantioselectivity (up to 90% ee) of substituted beta-naphthalenones. Various substituted 1-nitro-2-naphthols and MBH adducts are compatible under the optimized conditions. This reaction provides a convenient method for the synthesis of enantioenriched 1-nitro-beta-naphthalenone derivatives.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Shan-Shan Zhang, Jiahui Xue, Qing Gu, Xuefeng Jiang, Shu-Li You
Summary: The p-TsOH-catalyzed intermolecular dearomatization reactions of beta-naphthols with disulfurating reagents have been developed, leading to the smooth synthesis of various beta-naphthalenones bearing a quaternary carbon stereogenic center in good to excellent yields with high chemoselectivity. This reaction features mild reaction conditions and excellent functional group tolerance.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yunliang Yu, Zhenhao Zhang, Arnaud Voituriez, Nicolas Rabasso, Gilles Frison, Angela Marinetti, Xavier Guinchard
Summary: Stereocontrol in the enantioselective Au(i) catalyzed dearomatizations of 1-naphthols with allenamides is achieved through intramolecular ion-pairing between the chiral gold-tethered phosphate and an iminium unit, providing a rigid and well-defined chiral environment for the key electrophilic intermediate.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Hong-Wei Chen, Qin-Hua Song
Summary: This study presents a direct regioselective benzoyloxylative dearomatization of alpha- and beta-naphthols by benzoyl peroxide in an air atmosphere, under radical inhibitor- and catalyst-free conditions, at room temperature. The methodology offers a new efficient strategy for the construction of alpha-ketol derivatives with oxo-quaternary carbon center from naphthols with good to excellent yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Dong Gao, Lei Jiao
Summary: This study presents an efficient method for constructing indoline structures with a C2-quaternary stereocenter and controlling the migrating group through aza-semipinacol rearrangement. It enables the divergent access to dearomatized indole derivatives with either a C3- or a C2-quaternary stereocenter.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Ren-Xiao Liang, Ling-Jie Song, Jin-Bo Lu, Wei-Yan Xu, Chao Ding, Yi-Xia Jia
Summary: The study presents a PdH-catalyzed enantioselective heteroarenyne cycloisomerization reaction and a classical enantioselective 1,5-enyne cycloisomerization of N-vinylpropiolamides, showcasing the synthesis of diverse chiral spiro and fused indoline derivatives as well as chiral 2-pyrrolones with good to excellent enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Esteban Matador, Javier Iglesias-Siguenza, David Monge, Pedro Merino, Rosario Fernandez, Jose M. Lassaletta
Summary: A highly enantio- and diastereoselective thiourea-catalyzed dearomatization of isoquinolines has been developed using N-tert-butylhydrazones as key neutral reagents, leading to the formation of appealing dihydroisoquinoline derivatives with excellent stereocontrol. Experimental and computational data support the generation of highly ordered complexes that play a crucial role in the selective and high-yielding transformations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Braja Gopal Das, Sadhna Shah, Arko Das, Vinod K. Singh
Summary: The first stereoselective propargylic dearomatization of 2-naphthol derivatives was achieved using a chiral Cu-II-L10 complex, leading to the formation of products with a contiguous all-carbon quaternary-tertiary stereocenter and a terminal alkyne functionality. Both reactions demonstrated excellent chemodivergent reactivity and yielded the desired products with high chemo- and stereoselectivities.
Article
Chemistry, Multidisciplinary
Linqing Wang, Haiyong Zhu, Tianyu Peng, Yingfan Xu, Yanzhe Hou, Shixin Li, Shiming Pang, Hailong Zhang, Dongxu Yang
Summary: A catalytic asymmetric hydroxylative dearomatization reaction has been reported, and the resulting products can be easily converted into spiroannulation adducts by treatment with a base under mild conditions. Novel in-situ generated magnesium catalytic methods have been developed using combinational ligands. Related concise transformations of the spiroannulation adducts have been demonstrated.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Lu Bai, Xin Luo, Yicong Ge, Hui Wang, Jingjing Liu, Yaoyu Wang, Xinjun Luan
Summary: An enantioselective [4+1] spiroannulation reaction has been developed for the one-step construction of a new class of spirocyclic compounds. The mechanism of the reaction has been elucidated through mechanistic studies. Furthermore, the method shows great potential for various applications.
Article
Chemistry, Organic
Dongwei Zhao, Mengtian Liu, Lu Bai, Jingjing Liu, Xinjun Luan
Summary: A novel [4 + 1] and [5 + 1] dearomative spiroannulation method has been developed using commercial naphthols and phenols with dielectrophiles. Various spirocycles, including spiro[4.5] and spiro[5.5], were successfully constructed using four-atom or five-atom dielectrophilic synthons. This transformation proceeds through a sequence of site-selective C-alkylation/dearomative spiroannulation reactions. Furthermore, the potential application of this method was demonstrated by several additional transformations.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Mukesh Pappoppula, Kathryn L. Olsen, Devin R. Ketelboeter, Aaron Aponick
Summary: A highly enantioselective alkynylation of pyridine is reported. The reaction is enabled by StackPhos and proceeds with excellent regioselectivity (25 : 1), enantioselectivity (up to 99 % ee), and yield (up to 99 %). Terminal alkynes with a wide range of functional groups work well in the transformation, including acetylene gas, paving the way for the use of these feedstock starting materials to rapidly access highly useful synthetic intermediates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Qian Wan, Jia-Hao Xie, Chao Zheng, Yao-Feng Yuan, Shu-Li You
Summary: In this study, a catalytic asymmetric dearomatization reaction of electron-deficient heteroarenes with alpha-substituted isocyanoacetates was reported, leading to a range of optically active pyrrolo[3,4-b]indole derivatives. The reaction yielded good results with high stereoselectivities, using a catalytic system consisting of a cinchona-derived amino-phosphine and silver oxide. This method features wide substrate scope, mild conditions, and provides a new strategy for developing asymmetric dearomatization reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Alessandro Cerveri, Riccardo Giovanelli, Davide Sella, Riccardo Pedrazzani, Magda Monari, Olalla Nieto Faza, Carlos Silva Lopez, Marco Bandini
Summary: A novel asymmetric nickel-based procedure was developed for CO2 fixation in a truncated Heck coupling, leading to chiral products with enantiomeric excesses up to 99%. Combined experimental and computational efforts revealed the key steps of the catalytic cycle, including the unexpected participation of Ni(I) species in the coupling event.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Riccardo Pedrazzani, Juzeng An, Magda Monari, Marco Bandini
Summary: New chiral BINOL-based phosphate counterions have been synthesized and utilized in the gold-catalyzed enantioselective dearomatization reaction, leading to a range of densely functionalized C1-allylated naphthalenones with high levels of chemo-, regio-, and stereoselectivity (up to 95% ee).
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yang Liu, Simone Battaglioli, Lorenzo Lombardi, Arianna Menichetti, Giovanni Valenti, Marco Montalti, Marco Bandini
Summary: The study documents a visible-light photoredox/[Co(III)] cocatalyzed dehydrogenative functionalization of cyclic and acyclic styryl derivatives with carboxylic acids, leading to chemo- and regioselective allylic functionalization of styryl compounds, yielding allylic carboxylates. Both intermolecular and intramolecular variants are achieved in high yields, with a proposed mechanistic rationale based on experimental and spectroscopic investigation.
Article
Chemistry, Applied
Simone Battaglioli, Giulio Bertuzzi, Riccardo Pedrazzani, Jessica Benetti, Giovanni Valenti, Marco Montalti, Magda Monari, Marco Bandini
Summary: This study demonstrates the dehydrogenative functionalization of styryl carbon-carbon double bonds with triflamide via dual visible-light photoredox/cobaloxime catalysis. A variety of allylic triflamides were synthesized in moderate to good yields under stoichiometric acceptorless conditions (up to 88%). Our dedicated labelling and spectroscopic experiments provided insights into the concatenated photo- and chemo-catalytic cycles.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Lorenzo Lombardi, Alessandro Kovtun, Sebastiano Mantovani, Giulio Bertuzzi, Laura Favaretto, Cristian Bettini, Vincenzo Palermo, Manuela Melucci, Marco Bandini
Summary: This methodology involves environmentally friendly covalent functionalization of reduced graphene oxide (rGO) nanosheets with arylazo sulfones through visible-light irradiation. It allows various tagged aryl units to be conveniently accommodated on the rGO surface, with mild reaction conditions, absence of photosensitizers, functional group tolerance, and high atomic fractions. Control experiments for mechanistic elucidation (Raman analysis) and chemical nanomanipulation of the tagged rGO surfaces were also conducted.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Lorenzo Di Terlizzi, Simone Scaringi, Carlotta Raviola, Riccardo Pedrazzani, Marco Bandini, Maurizio Fagnoni, Stefano Protti
Summary: The synthesis of symmetrical (hetero)biaryls through arylation of sulfones using visible light irradiation and PPh3AuCl as the catalyst has been achieved. This protocol enables the efficient synthesis of a wide range of target compounds in an organic-aqueous solvent without the need for a photocatalyst.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Giulio Bertuzzi, Giada Ombrosi, Marco Bandini
Summary: This study demonstrates the effective and practical use of electrosynthesis for regio- and stereoselective alkylation of Morita-Baylis-Hillman compounds, resulting in high yields and wide functional group tolerance. It provides an efficient method for accessing densely functionalized cinnamate and oxindole derivatives.
Article
Chemistry, Multidisciplinary
Angela Pintus, Sebastiano Mantovani, Alessandro Kovtun, Giulio Bertuzzi, Manuela Melucci, Marco Bandini
Summary: Gram-scale synthesis and purification of new covalently modified GO-guanidine materials have been achieved, which demonstrate their application in the fixation of CO2 into cyclic carbonates. The protocol is characterized by mild operating conditions, high yields, wide scope, and recoverability/reusability of the material.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Physical
Riccardo Giovanelli, Giulio Bertuzzi, Marco Bandini
Summary: The utilization of CO2 as an efficient and environmentally friendly chemical analogue of CO is becoming a solid reality in the chemical scenario. CO2-based carbonylations have started paralleling the more consolidated carboxylation procedures, opening new horizons and perspectives in the utilization of carbon dioxide as an organic C1-containing building block. The advent of efficient and site-selective metal-catalyzed protocols for the fixation of CO2 into organic scaffolds, under controlled reductive conditions, contributed substantially to the development of robust, efficient, and convenient protocols. In the present Review article, a collection of the most recent examples of metal-catalyzed CO2-based carbonylations is documented with a particular emphasis on mechanistic aspects.
Article
Chemistry, Organic
Sebastiano Mantovani, Angela Pintus, Alessandro Kovtun, Giulio Bertuzzi, Manuela Melucci, Marco Bandini
Summary: A metal-free synthetic approach to functionalized indenes using graphene oxide (GO) is presented in this article. The method involves intramolecular Friedel-Crafts-type allylic alkylations with Morita-Baylis-Hillman alcohols. Experimental and spectroscopic investigations were conducted to understand the reaction mechanism involving a nanostructured carbon material-based C-C bond forming reaction. The results showed that this carbocatalysis approach is a viable option for the synthesis of indenes, with a wide scope and moderate to high yield under mild reaction conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Riccardo Giovanelli, Lorenzo Lombardi, Riccardo Pedrazzani, Magda Monari, Marta Castineira Reis, Carlos Silva Lopez, Giulio Bertuzzi, Marco Bandini
Summary: A carbonylation-carboxylation synthetic sequence is achieved via double CO2 fixation. The combination of Ni-catalyzed cross-electrophile coupling and AlCl3 triggers a cascade reaction resulting in the formation of three consecutive C-C bonds in a single operation. This strategy provides a novel synthesis route for ketones through Lewis acid-assisted carbon dioxide valorization, demonstrated by computational insights and labeling experiments.
Article
Chemistry, Organic
Riccardo Giovanelli, Lorenzo Lombardi, Riccardo Pedrazzani, Magda Monari, Marta Castineira Reis, Carlos Silva Lopez, Giulio Bertuzzi, Marco Bandini
Summary: This study presents a carbonylation-carboxylation synthetic sequence through double CO2 fixation. By utilizing AlCl3, a Ni-catalyzed cross-electrophile coupling reaction triggered a cascade reaction, resulting in the formation of three consecutive C-C bonds in a single operation. This strategy offers a novel synthetic route to ketones through Lewis acid assisted carbon dioxide valorization. Computational insights revealed the unique dual function of AlCl3, and labeling experiments with (CO2)-C-13 confirmed the genuine incorporation of CO2 in both functional groups.
Article
Chemistry, Multidisciplinary
Leonardo Rapisarda, Andrea Fermi, Paola Ceroni, Riccardo Giovanelli, Giulio Bertuzzi, Marco Bandini
Summary: We present the chemo- and stereoselective electrochemical allylation/alkylation of ethers via C(sp(3))-H activation. This electrosynthetic protocol allows for the synthesis of a diverse library of functionalized ethers (35 examples) in high yields (up to 84%) through cathodic activation of a new type of redox-active carbonate (RAC), which triggers HAT (Hydrogen-Atom-Transfer) events by generating electrophilic oxy radicals. The process demonstrates high functional group tolerance and mild reaction conditions. Mechanistic elucidation through voltammetric analysis completes the study.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Riccardo Pedrazzani, Emanuele Pinosa, Giulio Bertuzzi, Magda Monari, Samuel Lauzon, Thierry Ollevier, Marco Bandini
Summary: A new Au(i) catalyzed intramolecular hydrocarboxylation of allenes is presented, which serves as a valuable synthetic route to oxazino-indolones. The use of 3,5-(CF3)(2)-C6H3-ImPyAuSbF(6) as the optimal catalyst allows for wide tolerance of functional groups, mild reaction conditions, and high yields. Preliminary attempts towards an enantioselective version are also documented using a new family of chiral C-1-symmetric ImPyAuCl complexes.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Riccardo Pedrazzani, Angela Pintus, Roberta De Ventura, Marianna Marchini, Paola Ceroni, Carlos Silva Lopez, Magda Monari, Marco Bandini
Summary: A series of modular ImPy-carbene-Au(I) complexes were synthesized and characterized in both the solid state and solution. The incorporation of oligoaryl units at the C5-position of the ImPy core resulted in fine-tunable and predictable catalytic properties of the organometallic species. The presence of a CF3-containing aromatic ring at the ImPy core significantly accelerated several [Au(I)]-catalyzed electrophilic activations of unsaturated hydrocarbons.
ACS ORGANIC & INORGANIC AU
(2022)
