Article
Biochemistry & Molecular Biology
Ida Ziccarelli, Lucia Veltri, Tommaso Prestia, Roberta Amuso, Maria A. Chiacchio, Raffaella Mancuso, Bartolo Gabriele
Summary: Unreported 2-(4-acylfuran-2-yl)acetamides were selectively synthesized in fair to good yields (54-81%) over 19 examples through a mild catalytic process involving Csp-H activation, 5-exo-dig O-cyclization, and aromative isomerization.
Article
Chemistry, Multidisciplinary
Gilles De Smet, Xingfeng Bai, Carl Mensch, Sergey Sergeyev, Gwilherm Evano, Bert U. W. Maes
Summary: This study demonstrates that acetate can serve as a renewable leaving group for selective deoxygenation of phenolics. The Ni-catalyzed reaction in a green solvent allows for efficient deoxygenation without affecting specific functional groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Bowen Hu, Haoqiang Zhao, Yu Wu, Patrick J. Walsh
Summary: A novel, selective and high-yielding palladium-catalyzed carbonylative arylation of weakly acidic benzylic and heterobenzylic C(sp(3))-H bonds with aryl bromides has been achieved. The system allows access to diverse alpha-aryl or alpha,alpha-diaryl ketones, which are commonly found in biologically active compounds. The use of Josiphos SL-J001-1-based palladium catalyst enables the carbonylative arylation without the formation of direct coupling byproducts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Mario Martinez-Mingo, Andres Garcia-Viada, Daniel Sowa Prendes, Ines Alonso, Nuria Rodriguez, Ramon Gomez Arrayas, Juan C. Carretero
Summary: The selective delta-C(sp(3))-H acetoxylation of N-(SO2Py)-protected amino acid derivatives has been achieved using palladium-catalysis and PhI(OAc)(2) as both oxidant and acetoxy source. The unique structural and electronic features of SO2Py are crucial in overriding the more favorable intramolecular C-H amination.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Kaiting Zheng, Yaomei Liu, Chenggong Zheng, Fangpei Yan, Hua Xiao, Yi-Si Feng, Shilu Fan
Summary: A palladium-catalyzed monofluoroalkylation method using nucleophilic ethyl 2-fluoro-2-(trimethylsilyl)acetate as a monofluoroalkyl source was developed. The reaction exhibited excellent substrate scope, providing a range of monofluoroalkylated products in good yields under mild conditions. This protocol was successfully applied in the late-stage modification of an estrone derivative, offering a facile route for the discovery of biologically active compounds and high-performance materials.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Inaki Urruzuno, Paula Andrade-Sampedro, Arkaitz Correa
Summary: A Pd-catalyzed C(sp(2))-H acetoxylation method for Tyr-containing peptides is described, utilizing a removable 2-pyridyloxy group as a directing group. This method offers scalable and easily tunable regioselectivity for mono- and diacetoxylation reactions. Interestingly, the formation of L-DOPA peptidomimetics is hindered upon removal of the directing group.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Anurag Singh, Rahul K. Shukla, Chandra M. R. Volla
Summary: In this study, a novel nonoxidative [5 + 1] annulation reaction was reported. By using Rh(III) catalyst, 2-alkenylanilides and allenyl acetate were selectively reacted to obtain 1,2-dihydroquinoline derivatives. The reaction involves a series of steps including activation, insertion, elimination, and cyclization, achieving the construction of compounds. The method has a wide range of applications and can be used for functionalization of natural products.
Article
Chemistry, Physical
Caitlin Kozack, Stephen J. Tereniak, Jonathan N. Jaworski, Bao Li, David L. Bruns, Spring M. M. Knapp, Clark R. Landis, Shannon S. Stahl
Summary: This study focuses on the impact of benzoquinone on the catalytic activity in palladium(II)-catalyzed allylic acetoxylation. The results indicate that benzoquinone enhances the performance of the catalyst, showing a synergistic effect with Co(salophen) in improving reaction performance. The mechanistic studies suggest that both benzoquinone and oxygen play significant roles in oxidizing Pd(0) to Pd(II), leading to better reaction outcomes.
Article
Chemistry, Organic
Jin-Lin Wang, Mei-Ling Liu, Jian-Yu Zou, Wen-Hui Sun, Xue-Yuan Liu
Summary: This new strategy involves aminoarylation of alkenes by copper-catalyzed smiles rearrangement, using O-benzoylhydroxylamines as the amine reagent. It allows for the synthesis of beta-amino amide derivatives with a quaternary carbon center, showing wide functional group tolerance and high regioselectivity. Mechanistic studies suggest the involvement of aminyl radical intermediates under acid-free conditions.
Article
Chemistry, Organic
Muniyappa Vijaykumar, Chandini Pradhan, Rajesh G. Gonnade, Benudhar Punji
Summary: The palladium-catalyzed chemoselective oxygenation of C(sp2)-H and C(sp3)-H bonds in substituted isatin derivatives is described. This mild protocol allows for the C5 C(sp2)-H oxygenation of isatins through electrophilic intermolecular C-H palladation in concentrated solutions using PhI(OAc)2 or Selectfluor as an oxidant, while the N-CH3 C(sp3)-H oxygenation is achieved in dilute solutions via carbonyl-assisted intramolecular palladation in the presence of K2S2O8. This oxygenation reaction provides a direct and unified approach for synthesizing diverse oxygenated isatins with sensitive functionalities, including biorelevant compounds.
Article
Chemistry, Applied
Linhao Liu, Henri Doucet
Summary: The reactivity of 1,2-dihalobenzenes in palladium catalyzed polyheteroarylation via C-H bond functionalization was investigated. The first catalytic cycle using thiophene as the heteroarene gives the expected 2-(2-bromophenyl)thiophenes. In the course of the second catalytic cycle, in the presence of heteroarenes having a free C3-position, a partial Pd-1,4-migration occurred giving rise to aryl-substituted biheteroarenes such as 2 '-aryl-2,3 '-bithiophenes as well as the expected 1,2-di(thiophen-2-yl)benzenes. The best selectivities in favor of the formation of 2 '-aryl-2,3 '-bithiophenes were obtained with electron-rich 1,2-dihalobenzenes. A wide variety of thiophene derivatives bearing useful functions such as formyl, acetyl, cyclopropylmethanone, 2-methyl-1,3-dioxolane, ester, nitrile or chloro was tolerated allowing to prepare poly-functionalized 2 '-aryl-2,3 '-bithiophenes. Moreover, this one pot preparation of 2 '-aryl-2,3 '-bithiophenes employs a low loading of an air stable commercially available palladium source associated to an inexpensive base.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Javeed Ahmad Tali, Ravi Shankar
Summary: Here, we report an unprecedented protocol using ruthenium-catalyzed annulation for the synthesis of 6H-chromeno[4 ',3 ':4,5]imidazo[1,2-a]pyridin-6-one, and a new method for intramolecular chelation-assisted C-H activation to produce functionalized 2-(3-formylimidazo[1,2-a]pyridin-2-yl)phenyl acetate. Furthermore, a one-pot approach using ruthenium catalysis and formic acid has been developed for the gram-scale synthesis of bis(2-phenylimidazo[1,2-a]pyridin-3yl)methane (BIP) and the late-stage functionalization of zolimidine, a marketed drug, with good yield.
Article
Chemistry, Organic
Subarna Pan, Suparna Kundu, Rajarshi Samanta
Summary: This article describes a simple and efficient method for the synthesis of N-arylated 2-pyridone derivatives catalyzed by Rh(II), using 2-oxypyridine and diazonaphthoquinone as coupling partners. The reaction involves the insertion of the nitrogen atom of the 2-oxypyridine derivative into quinoid carbene and subsequent 1,6-benzoyl migratory rearrangement. The reaction exhibits broad scope and has the potential to provide axially chiral N-arylated 2-pyridone derivatives under suitable asymmetric conditions.
Article
Chemistry, Organic
Xinzhe Shi, Jian Zhang, Thierry Roisnel, Jean-Francois Soule, Henri Doucet
Summary: The reactivity of 2-benzyl-1,2,3-triazole in palladium-catalyzed direct arylation was investigated, leading to the selective synthesis of 2-benzyl-4-aryl-1,2,3-triazoles and subsequent synthesis of 4,5-diarylated 2-benzyl-1,2,3-triazoles. This selective 4,5-diarylation was successfully applied for the synthesis of pi-extended polycyclic heteroaromatic structures phenanthro[9,10-d][1,2,3]triazoles through Pd-catalyzed C4- and C5-intermolecular arylations followed by Pd-catalyzed C-H intramolecular arylation.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Pablo Losada, Laura Goicoechea, Jose Luis Mascarenas, Moises Gulias
Summary: This article describes the discovery and development of a palladium-catalyzed asymmetric C-H olefination of 2-hydroxybiaryls. The strategy allows a direct assembly of optically active, axially chiral 2-substituted-2'-hydroxybiaryls from readily available precursors and demonstrates the efficiency of the native hydroxy unit as a directing group for the C-H activation. Compared to other methods that require preinstallation of metal coordinating units, this approach offers simplicity and versatility, enabling the practical and efficient synthesis of a wide variety of optically active binaphthyl derivatives.
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)