Article
Chemistry, Organic
Sundaramoorthi Sarathkumar, Veerababurao Kavala, Ching-Fa Yao
Summary: A water-soluble and low-valent rhenium(I) catalyst has been described for the C2 alkenylation of N-pyridyl/N-pyrimidyl indole derivatives with ynamides under mild conditions using water as the solvent. The reaction results in high yields of C2-Z-selective alkenylation products.
Article
Chemistry, Organic
Balu Ramesh, Masilamani Jeganmohan
Summary: This paper describes a Co(III)-catalyzed regio- and chemoselective redox-neutral C-H annulation of arylamides/acrylamides with 1,3-dienes. The reaction is well-suited for less-reactive 1,3-butadiene and enables the synthesis of pharmaceutically important 3,4-dihydroisoquinolinones in good yields. The prepared 3,4-dihydroisoquinolinones can then be converted into highly important oxirane derivatives in good yields. A plausible mechanistic cycle is proposed and supported by a competition experiment and kinetic isotopic effect (KIE) studies.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
You-Feng Han, Ying Huang, Hao Liu, Zhong-Hua Gao, Chun-Lin Zhang, Song Ye
Summary: We developed a new method for the carboacylation of simple alkenes using a photoredox cooperative catalyst and unactivated alkyl halides, which provides ketones in high yields. This method has a wide scope of alkenes, broad functional group compatibility and does not require exogenous photosensitizer or external reductant.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Kausani Ghatak, Han Vinh Huynh
Summary: A library of neutral and cationic palladium complexes of cis-chelating hetero-dicarbene ligands have been prepared and their catalytic activities have been studied. It was found that complexes containing more distinct NHC units exhibited superior catalytic performance.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Qinghe Gao, Zhenhua Sun, Qinfei Xia, Ruonan Li, Wenlong Wang, Siwei Ma, Yixin Chai, Manman Wu, Wei Hu, Peter Abranyi-Balogh, Gyorgy M. Keseru, Xinya Han
Summary: A new general synthesis method has been developed to prepare pharmaceutically important azolo[1,5-a]pyrimidines starting from commonly available 3(5)-aminoazoles, aldehydes, and triethylamine. This direct and practical strategy allows the construction of a variety of compounds, including pyrazolo[1,5-a]pyrimidines and [1,2,4]triazolo[1,5-a]pyrimidines, with the capability to synthesize zaleplon, a clinically used drug.
Article
Chemistry, Multidisciplinary
Bo Zhang, Yu'ai Duan, Xin Zhang, Shuai Guo
Summary: The study reveals a new type of NHC-to-azole rearrangement, in which both the carbene backbone and the substituent are non-innocent. This is the first example of NHC-to-azole rearrangements for aryl-substituted NHCs.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Jiaming Wang, Changgui Zhao, Jian Wang
Summary: Axial chirality is widely present in natural products and pharmaceutical compounds, and recent advances in using NHC organocatalysts have opened up new opportunities for the synthesis of enantioenriched axially chiral molecules. This perspective highlights the importance of NHCs in catalyzing the synthesis of axially chiral scaffolds and serves as a stepping stone for future investigations in this area.
Article
Chemistry, Organic
Bholanath Garai, Molla Rahamat Ali, Rajib Mandal, Basker Sundararaju
Summary: This study demonstrates the C(8)-selective nucleophilic cascade cyclization of quinoline N-oxide with easily derived 1,6-enyne from phenol derivatives. Various quinoline N-oxide and alkynes are suitable for producing a library of quinoline N-oxide tethered cishydrobenzofurans with high yields and excellent functional group tolerance. The protocol's utility is achieved through post-synthetic modification of the cyclized product. Mechanistic studies suggest a base-assisted internal electrophilic-type substitution (BIES)-type pathway for C-H bond activation, and electrospray ionization mass spectrometry (ESI-MS) analysis confirms the formation of a key five-membered cobaltacycle.
Article
Chemistry, Physical
Darshana Bora, Stephy Elza John, Mary Sravani Galla, Manda Sathish, Nagula Shankaraiah
Summary: The rhodium-catalysed carbenes insertion strategy was developed to activate the non-acidic C-H bond of beta-carboline and isoquinoline scaffolds, allowing for facile C-C bond formation with high atom economy and wide functional group tolerance. Mechanistic insights were obtained and polycyclic indolizine-indole frameworks were successfully constructed.
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Zhen Liu, Zi-Yang Qin, Ledong Zhu, Soumitra Athavale, Arkajyoti Sengupta, Zhi-Jun Jia, Marc Garcia-Borras, K. N. Houk, Frances H. Arnold
Summary: Propargyl amines are versatile synthetic intermediates with numerous applications in the pharmaceutical industry. An enzymatic platform for enantioselective propargylic amination of alkynes using a hydroxylamine derivative as the nitrene precursor was developed in this study. The biocatalytic process showed high efficiency and selectivity, making it a promising approach for industrial applications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Bholanath Garai, Molla Rahamat Ali, Rajib Mandal, Basker Sundararaju
Summary: This study demonstrates the C(8)-selective nucleophilic cascade cyclization of quinoline N-oxide with easily derived 1,6-enyne from phenol derivatives. Various quinoline N-oxide and alkynes are found to be suitable for producing a library of quinoline N-oxide tethered cis-hydrobenzofurans with high yields and excellent functional group tolerance. The utility of the protocol has been achieved through post-synthetic modification of the cyclized product. Mechanistic studies reveal a base-assisted internal electrophilic-type substitution (BIES)-type pathway for C-H bond activation, and electrospray ionization mass spectrometry (ESI-MS) analysis confirms the formation of a key five-membered cobaltacycle.
Review
Chemistry, Multidisciplinary
Bei Zhang, Jian Wang
Summary: This article introduces the method of inserting fluorine atoms or assembling fluorine-containing fragments through NHC organocatalysis. By summarizing the relevant achievements, it provides enlightening clues for further development.
SCIENCE CHINA-CHEMISTRY
(2022)
Review
Biochemistry & Molecular Biology
Ziyang Dong, Chengming Jiang, Changgui Zhao
Summary: In this review, the generation and reactivity of NHC-bound alkynyl acyl azolium intermediates are summarized, covering the progress in the synthesis of achiral and axially chiral cyclic scaffolds via these intermediates. The mechanism related to this intermediate is discussed in detail.
Article
Chemistry, Organic
Jakub Brzeskiewicz, Rafal Loska
Summary: The palladium-catalyzed C(sp2)-H functionalization of bromoaryl aldonitrones leading to benzocyclobutenone-derived ketonitrones is described, allowing for the preparation of a wide range of strained, four-membered ketonitrones with broad functional group tolerance. Downstream transformations of the formed products were demonstrated, illustrating the synthetic utility of the obtained benzocyclobutenone-derived nitrones for the construction of polycyclic nitrogen-containing scaffolds.
Article
Chemistry, Organic
Wei-Jung Chiu, Ting-Yen Chu, Indrajeet J. J. Barve, Chung-Ming Sun
Summary: A Pd(II)-catalyzed [5 + 2] annulation reaction between N-triflyl aryl indoles and α,γ-substituted allenoates for the synthesis of indole-fused benzodiazepines is described. The use of N-acetylated valine amino acid as a ligand and DMSO as a cosolvent enhances the efficiency of this protocol. The reaction mechanism involves C-H activation, cyclopalladation, coordination, migratory insertion, reductive elimination, and [1,3]-H shift.
Article
Chemistry, Physical
Debasish Ghorai, Champak Dutta, Joyanta Choudhury
Article
Chemistry, Multidisciplinary
Ruli Borah, Arup Kumar Dutta, Parishmita Sarma, Champak Dutta, Bipul Sarma
Article
Chemistry, Multidisciplinary
Pirudhan Karak, Champak Dutta, Tanoy Dutta, Apurba Lal Koner, Joyanta Choudhury
CHEMICAL COMMUNICATIONS
(2019)
Article
Chemistry, Multidisciplinary
Champak Dutta, Arppitha Baby Sainaba, Joyanta Choudhury
CHEMICAL COMMUNICATIONS
(2019)
Article
Chemistry, Multidisciplinary
Ranjeesh Thenarukandiyil, Champak Dutta, Joyanta Choudhury
CHEMISTRY-A EUROPEAN JOURNAL
(2017)
Article
Chemistry, Multidisciplinary
Champak Dutta, Debasish Ghorai, Joyanta Choudhury