Article
Chemistry, Multidisciplinary
Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Summary: This study demonstrates the direct C2-functionalization of pyridines through a transition-metal-free protocol using aryne multicomponent coupling. The reaction allows for the synthesis of C2-substituted pyridine derivatives bearing the -CF3 group in good yields, with activated keto esters also being employed as third components in the formal 1,2-di(hetero)arylation of ketones. Performing the reaction under dilute conditions inhibits the competing pyridine-aryne polymerization pathway, leading to the desired products.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Shinya Tabata, Mai Minoshima, Akihiro Kobayashi, Takamitsu Hosoya, Suguru Yoshida
Summary: Migrative thioamination of aryne intermediates using o-iodoaryl triflates and sulfilimines leads to the formation of highly functionalized o-thioaminated diaryl sulfides. The ring expansion of cyclic sulfilimines enables the synthesis of eight- and nine-membered organosulfur compounds from dibenzothiophene- and thianthrene-type sulfilimines, respectively.
Article
Chemistry, Organic
Qunchao Zhao, Jean M. Etersque, Shuiyu Lu, Sanjay Telu, Victor W. Pike
Summary: In this study, we investigated the use of aryliodonium precursors for copper-free labeling of PET tracers with fluorine-18. We found that regioisomeric F-18-fluoroarenes can be formed in certain labeling methods. The reaction between aryliodonium ylides derived from Meldrum's acid with para electron-donating groups and [F-18]-fluoride in acetonitrile produces regioisomeric F-18-fluoroarenes via a competing aryne pathway. The formation of regioisomers is decreased or absent in DMF. It is recommended to analytically check for the absence of the F-18-regioisomer in any specific PET tracer radiosynthesis using these or similar methods.
Article
Chemistry, Organic
Xianda Wu, Yuqing Li, Minghong Chen, Fu-Sheng He, Jie Wu
Summary: A novel and efficient method for the synthesis of sulfilimines has been developed using diaryliodonium salts for the S-arylation of sulfenamides. The reaction proceeds smoothly under transition-metal-free and air conditions, resulting in good to excellent yields of sulfilimines via selective S-C bond formation. This scalable protocol exhibits a broad substrate scope, good functional group tolerance, and excellent chemoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Guoling Huang, Xunbo Lu, Fangpeng Liang
Summary: A transition-metal-free and redox-neutral synthesis of sulfilimines was achieved through the S-arylation of readily obtainable sulfenamides using diaryliodonium salts. The key step involved resonance between bivalent nitrogen-centered anions, leading to the deprotonation of sulfenamides under alkaline conditions and subsequent formation of sulfinimidoyl anions. Experimental results showed that sulfinimidoyl anionic species acted as effective nucleophilic reagents, providing sulfilimines with high yields and excellent chemoselectivity in a transition-metal-free protocol and under mild conditions.
Article
Chemistry, Physical
Gang Liu, Yuquan Qi, Jiashuai Li, Yifa Chen, Yilan Chen, Zhen Li, Guodong Shen, Delong Ma, Yunfeng Li, Xianqiang Huang
Summary: Four transition-metal lacunary polyoxometalates (TM-LPOMs) were used to fabricate ultra-low density foams, which were then used as catalysts for the efficient synthesis of sulfenamide rubber additives under mild conditions. The obtained additives showed superior rubber plastic properties and can be used in industrial rubber molding processes.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Organic
Huijie Qiao, Kun Zhao, Xilin Zhu, Xiaoxu Xu, Chunyang Wang, Lulu Zhong, Shixing Wang, Liting Yang, Dehong Yang, Guoqun Liu, Chunlei Lin, Mingli Jiao
Summary: A novel sulfenylation reagent (sulfenamide) was utilized to convert C-H bond in imidazo[1,2-a]pyridine to C-S bond in a simple and efficient manner. This process solely relies on sulfenamides as the sulfenylation reagent and I-2 as a cost-effective and readily available catalyst, eliminating the need for metal catalysts, oxidants, additives, or light radiation. The reaction exhibits excellent reactivity, substrate compatibility, and regioselectivity.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Manjot Kaur, Esha Sharma, Pushpinder Singh, Babaldeep Kaur, Amarjit Kaur, Kamal Nain Singh
Summary: A synthesis method for C-1 arylated benzazepines has been developed using a two-step protocol involving cyclization and deprotection, under transition-metal oxidant free conditions. The intramolecular coupling reaction of alpha-lithiated carbanion, generated from Boc-protected amine, with in situ generated aryne proceeds well, resulting in moderate yields of the desired products.
Article
Chemistry, Organic
Xiaolong Guo, Pingping Li, Qing Wang, Qi Wang, Luyao Wang
Summary: A facile transition metal-free decarboxylative C4 selective C-H difluoroarylmethylation of 8-aminoquinolines under simple aqueous conditions has been developed, providing a novel and concise route for the construction of a difluoromethylene linker between (hetero)aromatic rings (Ar-CF2-Ar). Initial mechanistic studies suggest the involvement of a reasonable radical coupling reaction in this C4 selective C-H difluoroarylmethylation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Wenhao Tang, Boya Li, Kewei Teng, Xiaodong Wang, Ruiping Liu, Mengwei Wu, Lei Zhang, Pengfei Ren, Junqing Zhang, Ming Feng
Summary: This review focuses on the sluggish reaction kinetics at the oxygen cathode in metal-air batteries, which is a major obstacle to their commercialization. The use of noble-metal electrocatalysts has been a potential solution, but their high cost and scarcity hinder their widespread application. The review discusses the mechanisms of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), proposes principles for bifunctional electrocatalysts, and presents state-of-the-art catalysts based on carbon and transition-metal materials. Additionally, it explores self-supporting 3D noble-metal-free bifunctional ORR/OER catalysts and provides perspectives on the future development of bifunctional electrocatalysts.
JOURNAL OF MATERIOMICS
(2022)
Article
Chemistry, Organic
Pei-Wen Yang, Xin-Xin Liu, Xue-Qiang Li, Meng-Xue Wei
Summary: Inexpensive and easily accessible calcium carbide has been developed as a promoter for the transition metal-free, solvent-free and one-pot conversion of acid chlorides and DMSO to beta-keto sulfoxides. Four drug molecules were successfully converted to their beta-keto sulfoxides using this method, highlighting its potential utility in medicinal chemistry.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Multidisciplinary
Rui Wei, Shaoying Ju, Liu Leo Liu
Summary: We report a facile and highly modular access to an intriguing class of free Au-substituted phosphines (AuPhos). Au-substitution can boost the electron-releasing ability of AuPhos, leading to an electronically and sterically tunable, extremely electron-rich phosphorus center. Multi-nuclear transition metal complexes ligated by AuPhos are readily prepared, and preliminary catalytic results show the facilitation of C-N coupling reactions and decarbonylation reactions. This work provides insights for future development of electron-rich ligands.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xinyu Chen, Na Yang, Wen Zeng, Lei Wang, Pinhua Li, Hongji Li
Summary: A mild dearomative [5+2]/[2+2] cycloaddition of 1H-indoles with ortho-(trimethylsilyl)aryl triflates was reported, leading to the synthesis of dibenzo[b,e]azepine derivatives in moderate to good yields. Increasing steric hindrance at the C2-position of 1H-indoles directs the reaction towards a [2+2] cycloaddition pathway. Mechanistic investigations suggest that the reaction proceeds through a [2+2] cycloaddition followed by a ring expansion to form the [5+2] cycloaddition product.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Yaling Xu, Jieyi Gao, Caihong Wang, Yunfei Ma, Jun Zhou, Ge Wu
Summary: The copper-catalyzed oxidative aminophosphorothiolation of maleimides with secondary alkylamines and diethylphosphorodithioate has been established, providing a concise pathway to access structurally diverse beta-amino vinyl phosphorodithioates. The utility of this protocol is further highlighted in late-stage vinylphosphorothiolation of amine-containing drug fragments.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Gurupada Hazra, Gitanjali Mishra, Rambabu Dandela, Barla Thirupathi
Summary: The dibenzobicyclo[3.2.1]octadienone scaffold, found in various compounds such as naphthocyclinones, engelharquinones, and rubialatin A, has been successfully synthesized using a mild transition metal-free aryne insertion reaction. The methodology has been applied to the synthesis of the 6/6/5/6/6 scaffold of rubialatin A. H-1 NMR experimental studies confirm the reaction mechanism involves the formation of a benzocyclobutane followed by a 7-member carbocycle ring.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Santigopal Mondal, Santhivardhana Reddy Yetra, Subrata Mukherjee, Akkattu T. Biju
ACCOUNTS OF CHEMICAL RESEARCH
(2019)
Article
Chemistry, Physical
Tamal Kanti Das, Avik Ghosh, Kuruva Balanna, Pradipta Behera, Rajesh G. Gonnade, Udaya Kiran Marelli, Abhijit Kumar Das, Akkattu T. Biju
Article
Chemistry, Organic
Subrata Bhattacharjee, Avishek Guin, Rahul N. Gaykar, Akkattu T. Biju
Article
Chemistry, Multidisciplinary
Tony Roy, Anu Jacob, Subrata Bhattacharjee, Akkattu T. Biju
CHEMISTRY-AN ASIAN JOURNAL
(2019)
Article
Chemistry, Organic
Avishek Guin, Rahul N. Gaykar, Subrata Bhattacharjee, Akkattu T. Biju
JOURNAL OF ORGANIC CHEMISTRY
(2019)
Article
Chemistry, Organic
Rahul N. Gaykar, Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Article
Chemistry, Multidisciplinary
Subrata Bhattacharjee, Anjali Raju, Rahul N. Gaykar, Rajesh G. Gonnade, Tony Roy, Akkattu T. Biju
CHEMISTRY-AN ASIAN JOURNAL
(2020)
Article
Chemistry, Organic
Rahul N. Gaykar, Malini George, Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Summary: This study presents an oxa-[2,3] sigmatropic rearrangement involving arynes, with the reversal of the C=O bond polarity in ketones. The in situ-generated sulfur ylides from beta-keto thioethers and arynes undergo efficient rearrangement to synthesize functionalized enol ethers with high yields and excellent functional group compatibility. Preliminary mechanistic studies suggest that a Pummerer-type rearrangement is not operating in this case.
Article
Chemistry, Multidisciplinary
Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Summary: This study demonstrates the direct C2-functionalization of pyridines through a transition-metal-free protocol using aryne multicomponent coupling. The reaction allows for the synthesis of C2-substituted pyridine derivatives bearing the -CF3 group in good yields, with activated keto esters also being employed as third components in the formal 1,2-di(hetero)arylation of ketones. Performing the reaction under dilute conditions inhibits the competing pyridine-aryne polymerization pathway, leading to the desired products.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Subrata Bhattacharjee, Shiksha Deswal, Niket Manoj, Garima Jindal, Akkattu T. Biju
Summary: This study demonstrates a facile synthesis of biologically important S-aryl dithiocarbamates through aryne three-component coupling, and presents preliminary mechanistic experiments. Additionally, a unique four-component coupling reaction was observed.
Article
Chemistry, Organic
Rahul N. Gaykar, Shiksha Deswal, Avishek Guin, Subrata Bhattacharjee, Akkattu T. Biju
Summary: This study demonstrates the synthesis of 2,4,5-trisubstituted oxazoles through a transition-metal-free chemical reaction under mild conditions. The desired products were obtained through a series of reaction steps.
Article
Chemistry, Organic
Subrata Bhattacharjee, Avishek Guin, Rahul N. Gaykar, Akkattu T. Biju
Article
Chemistry, Multidisciplinary
Tony Roy, Rahul N. Gaykar, Subrata Bhattacharjee, Akkattu T. Biju
CHEMICAL COMMUNICATIONS
(2019)
