Article
Chemistry, Organic
Eunjae Chung, Suho Kim, Amitava Rakshit, Pargat Singh, Jaewook Park, Taejoo Jeong, In Su Kim
Summary: In this study, the rhodium(III)-catalyzed C8-spiroannulation of 1-aminonaphthalenes with maleimides is investigated. The resulting C8-alkenylated 1-aminonaphthalenes can further react with nucleophilic 1-amino groups through intramolecular aza-Michael reaction, leading to the formation of spirofused tetracyclic frameworks. This method demonstrates a broad substrate scope and compatibility with various functional groups.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
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).
Article
Chemistry, Multidisciplinary
Hong Hu, Bin-Shi Li, Jing-Lei Xu, Wei Sun, Yong Wang, Meng Sun
Summary: This study developed an unprecedented Rh(iii)-catalyzed reaction for the synthesis of spiro[4,5]dienone compounds. The method exhibits excellent selectivity and wide functional group tolerance.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Yichun Wang, Deyang Jia, Jing Zeng, Yuming Liu, Xiubin Bu, Xiaobo Yang
Summary: A visible-light-accelerated Rh(III)-catalyzed C-H annulation of aromatic amines with bicyclic alkenes was developed for the synthesis of benzocarbazole derivatives. The reaction proceeded smoothly at room temperature, delivering good to excellent yields of bridged oxa or aza tetrahydro benzocarbazoles. Furthermore, benzo[b]carbazoles were conveniently synthesized through further aromatization in one pot, showcasing the method's potential for various applications.
Article
Chemistry, Organic
Jian Zhou, Chuanliu Yin, Tianshuo Zhong, Xiangyun Zheng, Xiao Yi, Junyu Chen, Chuanming Yu
Summary: A rhodium (III)-catalyzed [4 + 1] spiroannulation of N-aryl phthalazine-diones (pyridazine-diones) with diazo compounds was described to construct spirocyclic indazole derivatives with diverse structures. The corresponding products were obtained in moderate to good yields, and the reaction involves C-H activation, carbene insertion, and a nucleophilic addition process. Additionally, the method features high atom-economy and high functional group tolerance.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Bingxian Liu, Lingyun Yang, Zhenzhen Dong, Junbiao Chang, Xingwei Li
Summary: The rhodium(III)-catalyzed annulation of 2-biphenylboronic acids with activated alkenes has been achieved, leading to the synthesis of fused or bridged cyclic skeletons via transmetalation-initiated C-H activation. The bulky cyclopentadienyl ligand in the catalyst promoted reductive elimination and led to the formation of [4 + 2] annulated products. The substrate scope was broad, with high yields of up to 99% obtained under air-tolerant conditions.
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, Multidisciplinary
Christopher W. Lamartina, Cassandra A. Chartier, Sumin Lee, Neel H. Shah, Tomislav Rovis
Summary: Here, a modular peptide ligation methodology is reported, which uses Rh(III) catalysis to couple dioxazolones, arylboronic acids, and acrylamides to construct amide bonds in a diastereoselective manner under mild conditions. The method shows excellent functional group tolerance and a large substrate scope, allowing for the construction of unnatural amino acid residues. This methodology is demonstrated in the synthesis of diastereomeric proteasome inhibitor analogs and the ligation of oligopeptides to construct a polypeptide with an unnatural residue.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Daijiao Zhuang, Tharcisse Gatera, Zhenyu An, Rulong Yan
Summary: A new method for synthesizing 1-pyrrolines from cyclobutanol derivatives and an aminating reagent has been developed, achieving C-N bond/C = N bond formation via ring expansion. A series of 1-pyrroline derivatives are synthesized in moderate to good yields under mild conditions.
Article
Chemistry, Organic
Daijiao Zhuang, Tharcisse Gatera, Zhenyu An, Rulong Yan
Summary: A method for the synthesis of 1-pyrrolines from cyclobutanol derivatives and an aminating reagent has been developed. The one-pot procedure achieves the formation of C-N bond/C = N bond via ring expansion, leading to the synthesis of a series of 1-pyrroline derivatives in moderate to good yields under mild conditions.
Article
Chemistry, Physical
Nicolas R. Ball-Jones, Angel A. Cobo, Brittany M. Armstrong, Benjamin Wigman, James C. Fettinger, Jason E. Hein, Annaliese K. Franz
Summary: A mechanism for scandium-catalyzed asymmetric allylsilane annulation reaction is proposed and supported by experimental evidence. The study reveals the effects of catalyst solubility, coordination sequence, and timing of nucleophile addition on the reaction rate. Ligand-dependent acceleration of the catalysis is observed.
Article
Chemistry, Organic
Masilamani Jeganmohan, Chikkabagilu Nagaraju Shambhavi
Summary: A Rh(III)-catalyzed weak enone carbonyl/ketone-assisted aerobic oxidative C-H olefination of aromatics with unactivated alkenes has been developed, allowing for the transformation of various substituted biologically relevant chalcones and aromatic ketones with functionalized unactivated olefins in moderate to good yields.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Writhabrata Sarkar, Koushik Naskar, Shantonu Roy, Imtiaj Mondal, Sudip Karmakar, Aniket Mishra, Indubhusan Deb
Summary: We reported a novel atom-economic catalytic reaction for the synthesis of spirocycles by reacting cyclic ketimines with α,β-unsaturated carbonyl compounds. This reaction allows the formation of three stereogenic centers in one pot and does not require any silver additives or external oxidants. It has a wide substrate scope and good functional group tolerance, leading to the synthesis of polysubstituted α-aroyl-indanamines in high diastereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Hui Xie, Jin-Yi Liang, Zhuo-Jun Huang, Bing Shu, Yi-Chuan Zheng, Yan-Zhi Liu, Shao-Yong Chen, Xu-Ge Liu, Shang-Shi Zhang
Summary: A Rh(iii)-catalyzed tandem reaction using 5-methylene-1,3-dioxan-2-one as an efficient allyl source has been developed for the synthesis of 3,4-dihydropyrimido[1,6-a]indol-1(2H)-ones, showing good substrate scope and moderate to excellent yields. The Rh(iii) catalyst plays a dual role in C-H activation and N-alkylation annulation process in the mechanism studies.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Nan Ma, Zheyuan Liu, Jianhui Huang, Yanfeng Dang
Summary: Density functional theory calculations have revealed the mechanism and origins of the reactivity and regioselectivity of the Cp*Ir(iii)/Cp*Rh(iii)-catalyzed allylic C-H amidation. The rate-determining step is found to be the C-H activation, which differs between the Cp*Ir(iii) and Cp*Rh(iii) systems, affecting their reactivity and regioselectivity. The insights provided by this study will be valuable for the development of transition metal-catalyzed selective C-H amination reactions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
