Article
Chemistry, Multidisciplinary
Mingqin Zhao, Xinyan Li, Xiaoyu Zhang, Zhihui Shao
Summary: The catalytic dehydrogenation of alcohols is crucial for sustainable production of valuable products, providing a new strategy for green organic synthesis in chemical industries. This study introduces a manganese-based catalytic system that efficiently synthesizes C3-alkylated indoles from benzyl alcohols and indoles via the borrowing hydrogen process. Furthermore, dehydrogenative coupling of 2-arylethanols and indoles yields C3-alkenylated indoles. Additionally, reacting 2-aminophenethanol instead of indoles under the same conditions also yields the corresponding indole products with high selectivity.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Organic
Kai Chen, Qian Liu, Jinyan Wan, Chuan Zhu, Chao Feng
Summary: A Ni-catalyzed reductive dicarbofunctionalization of α-CF3 styrenes with benzyl bromides has been achieved, which overcomes the facile β-F elimination and allows the creation of CF3-substituted all-carbon quaternary centers with pharmaceutical significance. Preliminary mechanistic studies suggest a pathway involving benzyl radical addition and subsequent nickel-mediated benzylation of the resulting α-CF3-embedded tertiary C radical.
Article
Chemistry, Organic
Teruhisa Tsuchimoto, Takahiro Johshita, Kazuhiro Sambai, Naoki Saegusa, Takumi Hayashi, Tomohiro Tani, Mana Osano
Summary: A new method for the formation of seven-membered carbon rings in heteroarylindoles reacting with different substrates was discovered in this study, and the two different annulation reactions could be controlled. The resulting tetracyclic products can be further extended through subsequent reactions to expand the p-conjugated region.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Applied
Yaoguang Sheng, Yi Gao, Bingbing Duan, Mengxia Lv, Yao Chen, Mengjie Yang, Jianmin Zhou, Guang Liang, Zengqiang Song
Summary: A versatile and efficient method for the coupling of maleimides and indoles at the C7-position has been established under Rh(III) catalysis. The protocol is compatible with various functional groups, and yields diverse 3-(indol-7-yl) maleimides and 3-(indol-7-yl)succinimides by switching reaction conditions. Deuteration studies and control experiments have been carried out to explore the mechanism of this transformation.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Yifei Qu, Xiaojia Cai, Yuzhuang Guan, Jiamin Tan, Zhangping Cai, Minyun Liu, Yasi Huang, Jinhui Hu, Wen-Hua Chen, Jia-Qiang Wu
Summary: A facile and straightforward method for the successful synthesis of difluoromethylated indole-3-carbinols, bisindolylmethanes, and indole-3-methanamines by a Friedel-Crafts reaction is developed, showing good to excellent yields, broad substrate compatibility, good functional group tolerance, and scalability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Luigi Dolcini, Tommaso Gandini, Riccardo Castiglioni, Alberto Bossi, Marta Penconi, Alberto Dal Corso, Cesare Gennari, Luca Pignataro
Summary: This study investigates the use of organic photocatalysts for visible light-promoted beta-functionalization of carbonyl compounds. Donor-acceptor cyanoarenes showed the best results among the tested dyes, promoting the desired transformations in moderate to good yields. The reaction scope was explored on substrates with different steric and electronic properties, and a reductive quenching mechanism involving a transient 5 pi e(-) activation mode was proposed based on fluorescence quenching analysis.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Subhendu Pramanik, Sarat Chatterjee, Rumjhum Banerjee, Chinmay Chowdhury
Summary: This study presents a direct synthesis method for carbazoles containing aryl and aryl ketone groups. The reaction involves Pd(II)-catalyzed cascade reactions, which enables the fast assembly of carbazoles through four carbon-carbon bond formations. The absence of aldehyde substrates leads to the formation of C4-aryl-substituted carbazoles. The method is versatile for the synthesis of biscarbazole derivatives.
Article
Chemistry, Organic
Yuanfeng Li, Hong-Yu Zhang, Yuecheng Zhang, Ya-Ping Han, Jiquan Zhao, Yong-Min Liang
Summary: A novel Pd-catalyzed asymmetric intra-molecular cascade cyclization has been developed for the synthesis of indoline derivatives through a dearomative Heck reaction, showing excellent yields and chiral selectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Wei Tian, Bowen Li, Duanshuai Tian, Wenjun Tang
Summary: A palladium-catalyzed 2-alkylation of indoles with alpha-bromo esters using a P,P=O ligand has been developed. The method shows excellent regioselectivities, mild reaction conditions, and good functional group compatibility. Mechanistic studies indicate that the reaction proceeds through a radical pathway.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Organic
Kensuke Kiyokawa, Naruyo Urashima, Satoshi Minakata
Summary: In this study, a method for the C3 cyanoalkylation of indoles using cyanohydrins in the presence of a B(C6F5)(3) catalyst was reported. Mechanistic investigations revealed the unique reactivity of the B(C6F5)(3) catalyst in promoting the decomposition of cyanohydrins. Additionally, a catalytic three-component reaction using indoles, aldehydes, and acetone cyanohydrin was developed for the synthesis of various types of indole-3-acetonitrile derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Takashi Mino, Yohei Fujisawa, Shizuki Yoshida, Mitsuru Hirama, Takumu Akiyama, Ryo Saito, Yasushi Yoshida, Yoshio Kasashima, Masami Sakamoto
Summary: By synthesizing cinnamoyl amide type chiral P,olefin ligand (S)-4, separable diastereomers of 4d were obtained successfully, and asymmetric allylic substitution reactions of indoles using (S,aS)-4d as a chiral ligand demonstrated high enantioselectivities (up to 98% ee).
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Xi Xiao, Xiaobiao Lu, Ming Zhang, Haoqing Hou, Changfeng Wan, Jinbiao Liu
Summary: A novel synthetic method was successfully developed for the preparation of multisubstituted dihydrochromeno[2,3-b]indole derivatives in moderate to high yields using a catalytic environmentally benign iron salt.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Kouki Tsuge, Shunnichi Kubota, Kana Sakamoto, Kenji Kitayama, Takahiro Nishimura
Summary: This study demonstrated the successful iridium-catalyzed alpha-alkylation of methyl ketones with primary carbohydrate alcohols using the borrowing hydrogen strategy. Protected sugar derivatives with one free primary hydroxyl group reacted with methyl ketones, resulting in the formation of alpha-alkylation products or alkylated 4,5-unsaturated sugars, accompanied by the elimination of an alkoxy group.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Qin Shi, Haiyan Hu, Minxing Du, Yajun Sun, Yudong Li, Yuehui Li
Summary: In this study, CO2/H2 was used as a methylation reagent for selective C-H methylation of heteroarenes. The reaction was catalyzed by cobalt/B(C6F5)3, and the Lewis acidic additive B(C6F5)3 played a crucial role in achieving good reactivity. The reaction proceeds via CO2 reduction, C-C bond formation, and reduction. Water is the only byproduct of this environmentally friendly alternative for C-H methylation.
Article
Chemistry, Organic
Takashi Mino, Kaho Takaya, Kaito Koki, Natsume Akimoto, Yasushi Yoshida, Yoshio Kasashima, Masami Sakamoto
Summary: We synthesized N-alkyl-N-cinnamoyl amide type phosphine-olefin compounds 1 and observed axial chirality in the C(aryl)-N(amide) bond of compounds 1 using HPLC analysis with a chiral stationary phase column. Enantiomeric isomers of 1 were obtained and (-)-1 was demonstrated as a chiral ligand in Pd-catalyzed asymmetric allylic substitution reactions, leading to high enantioselectivity (up to 97% ee) in the esterification process.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
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)