Article
Chemistry, Physical
Manikantha Maraswami, Thomas Diggins, Jeffrey Goh, Raymond Tio, Wan Qing Renee Ong, Hajime Hirao, Teck-Peng Loh
Summary: This study presents a highly selective synthesis method for indene or 1-naphthol derivatives through intramolecular alkene-alkene cross-coupling, which works with different alkene pairs to give products in good to satisfactory yields. The indene products of the reaction allow further derivatization, and the reaction pathway is dependent on alkene functionalities.
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, Organic
Shravani Battula, Hemalatha Bukya, Kunta Chandra Shekar, Kiranmai Nayani
Summary: A Rh(III)-catalyzed annulation was achieved between 2-arylimidazo[1,2-a]pyridines and p-quinols, leading to the formation of bridged heterocycles with three contiguous stereocenters via a twofold conjugate addition. The cascade reaction showed diastereoselectivity and proceeded through a sequential Rh-catalyzed ortho C(sp(2))-H functionalization of the aryl group of imidazo[1,2-a]pyridine with p-quinol, followed by an intramolecular conjugate addition, to produce a series of diverse and novel bridged heterocycles.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Alexandra S. Bubnova, Daria V. Vorobyeva, Ivan A. Godovikov, Alexander F. Smol'yakov, Sergey N. Osipov
Summary: An efficient method for accessing CF3-containing spiro-[indene-proline] derivatives has been developed through a Cp*Rh(III)-catalyzed tandem C-H activation/[3+2]-annulation reaction between 5-aryl-2-(trifluoromethyl)-3,4-dihydro-2H-pyrrole-2-carboxylates and alkynes. Remarkably, the dehydroproline moiety acts as a directing group, enabling selective activation of aromatic C-H bond.
Article
Chemistry, Organic
Haosheng Li, Mingjing Mei, Lei Zhou
Summary: A Rh(III)-catalyzed defluorinative [4 + 2] annulation was developed using 2-diazo-3,3,3-trifluoropropanoate as a nontraditional two-carbon reaction partner, leading to the synthesis of 1,3,4-functionalized isoquinolines.
Article
Chemistry, Multidisciplinary
Shawn M. Moore, Chen Sun, Jennifer L. Steele, Ellen M. Laaker, Arnold L. Rheingold, Linda H. Doerrer
Summary: There is a strong interest in MnOHx moieties due to the stepwise changes in O-H bonds with Mn oxidation state changes. The reactivity of aquo-derived ligands, {MOHx}, is influenced by the electronic character of other ligands. Preparation of mononuclear Mn complexes with all O-donors is rare despite oxygen coordination being prevalent in biological systems.
Article
Chemistry, Multidisciplinary
Min Wu, Haiman Zhang, Ting Wang, Shuang Lin, Ziyang Guo, Hui Gao, Zhi Zhou, Wei Yi
Summary: In this study, the Rh(III)-catalyzed chemo-, regio-, and stereoselective carboamination of sulfonyl allenes has been achieved. This reaction utilizes N-phenoxy amides or N-enoxy imides as both C and N sources, and proceeds via a redox-neutral tandem C-H activation/allene insertion/oxidative addition/C-N bond formation pathway, enabling the direct construction of allylamine derivatives with an alpha-quaternary carbon center. The protocol demonstrates high atom-economy and good substrate compatibility, highlighting its synthetic potential for late-stage C-H modification of complex molecules.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Edgardo De Leon, Fernando Gonzalez, Preetika Bauskar, Sergio Gonzalez-Eymard, David De Los Santos, Manar M. Shoshani
Summary: We report a novel methodology to amplify the reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. The catalytic hydroboration of quinolines was significantly altered by the addition of a secondary metal to bridge the Al-hydride species LAlH. This leads to the formation of novel heterotrimetallic species 1, which exhibits catalytic hydroboration of sterically encumbered quinolines and approximately a 400 times enhancement in catalytic reactivity in comparison to LAlH.
Article
Chemistry, Physical
Seongho Jin, Jinwoo Kim, Dongwook Kim, Jung-Woo Park, Sukbok Chang
Summary: In this study, a Rh-catalyzed C-H acyloxylation under mild electrolytic conditions was developed, with anodic oxidation of a key rhodacyclic carboxylate intermediate enabling the product-releasing C-O bond-forming reductive elimination process. The accumulation of carboxylate near the electrode surface further induced the desired C-O bond formation, allowing ambient catalytic C-H oxygenation using stoichiometric amounts of readily accessible carboxylic acid coupling partners.
Article
Chemistry, Organic
Tao Liu, Lingli Han, Jing Zhang, Gang Lu
Summary: Density functional theory calculations were used to investigate the competing pathways of rhodacycle intermediates in Rh(III)-catalyzed annulations of 2-alkenyl phenols and 2-alkenyl anilides with alkynes. The results reveal that the multiple pathways of eight-membered rhodacycles can be subtly tuned to give specific cyclic products. The formation of different cyclic products from 2-alkenyl phenols and 2-alkenyl anilides is governed by different pathways involving the dissociation of Rh-O bond and intramolecular olefin migratory insertion, respectively.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Mu-Jia Luo, Gui-Fen Lv, Jing-Hao Qin, Chong-Hui Xu, Yang Li, Jin-Heng Li
Summary: This study presents a rhodium-catalyzed electrochemical reaction for the selective synthesis of structurally diverse hexasubstituted arenes. The method demonstrates excellent selectivity and high atom economy.
Article
Chemistry, Multidisciplinary
Mu-Jia Luo, Gui-Fen Lv, Jing-Hao Qin, Chong-Hui Xu, Yang Li, Jin-Heng Li
Summary: A cooperative rhodium-catalyzed electrochemical 1,3-butadiyne [2 + 2 + 2] cyclotrimerization is presented, which selectively produces hexasubstituted arenes. The method features high selectivity, good functional group tolerance, and high atom economy.
Article
Chemistry, Multidisciplinary
Daigo Hayashi, Tomohiro Tsuda, Ryo Shintani
Summary: A palladium-catalyzed skeletal rearrangement has been developed to synthesize highly fused tetrahydrophenanthrosilole derivatives via bond exchange. The reaction conditions can be tuned to produce different products, fused dihydrodibenzosilepin derivatives.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Pothapragada S. K. Prabhakar Ganesh, Perumal Muthuraja, Purushothaman Gopinath
Summary: This report demonstrates a hydrazine-directed, Rh(iii) catalyzed (4+2) annulation reaction using sulfoxonium ylides as a safe carbene precursor. The reaction exhibits excellent functional group tolerance, broad substrate scope, scalability, and site selectivity. Additionally, photophysical studies suggest that some compounds formed in this reaction possess interesting fluorescence properties.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Rohit Sarthi, Rohit Kumar, Tamanna Sharma, Upendra Sharma
Summary: In this study, a concise Rh(III)-catalyzed C(sp3)-H alkylation of 8-methylquinolines with oxabenzonorbornadiene scaffolds and other strained olefins was presented. The developed catalytic methodology exhibits key features such as the retention of the oxabenzonorbornadiene skeleton, broad substrate scope, and wide-ranging functional group tolerance. Mechanistic studies revealed that the reaction proceeds through a non-radical pathway, with the five membered rhodacycle serving as the key intermediate. This is the first report on the C(sp3)-H alkylation of 8-methylquinolines with strained oxabenzonorbornadiene scaffolds (with ring retention).
