Article
Chemistry, Organic
Prakriti Dhillon, Prasad Anaspure, Jesper G. Wiklander, Subban Kathiravan, Ian A. Nicholls
Summary: The regiochemical outcome of a cobalt(ii) catalysed C-H activation reaction of aminoquinoline benzamides with unsymmetrical 1,3-diynes under relatively mild reaction conditions can be controlled by the choice of diyne. The choice of diyne allows access to either 3- or 4-hydroxyalkyl isoquinolinones, facilitating the synthesis of more complex isoquinolines.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Cheng Li, Huawen Huang, Fuhong Xiao, Bin Zhao, Guo-Jun Deng
Summary: The study describes a practical strategy for skeletal diversification through combining selective C-H cleavage with C-C cleavage in a tandem reaction. Rhodium(iii)-catalyzed redox-neutral reaction of aryl oximes and internal alkynes generates novel N-(2-cyanoaryl) indanone imines with good yields, regioselectivities and atom economy, producing water as the only by-product. Experimental and theoretical studies offer mechanistic insights into this transformation, achieving an attractive integration of C-H activation with C-C activation in oxime transformation.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Rajshekhar A. Unhale, Milon M. Sadhu, Vinod K. Singh
Summary: A novel organocatalytic asymmetric formal [3 + 2] cycloaddition has been developed for the synthesis of biologically relevant chiral spiroisoindolinone-indolines with excellent yields and enantioselectivity under mild conditions.
Article
Chemistry, Organic
Jun-Nan Li, Zi-Jie Li, Liu-Yu Shen, Pinhua Li, Yicheng Zhang, Wen-Chao Yang
Summary: A selective polychloromethylation and halogenation reaction of alkynes was disclosed using a radical addition/spirocyclization cascade sequence. By utilizing polyhaloalkanes as precursors for polyhalomethyl and halogen radicals, a series of valuable spiro[5,5]trienones containing halogen-, CHCl2-, or CCl3-groups were synthesized in good yields under simple and mild conditions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
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.
Review
Chemistry, Multidisciplinary
Arijit Saha, Majji Shankar, Somratan Sau, Akhila K. Sahoo
Summary: Transition-metal catalyzed directing group assisted annulation of inert C-H bonds is a method for constructing complex molecular frameworks from readily accessible substrates. It allows the activation of directed inert C-H bonds and migration of transition metals, leading to the formation of structurally diverse fused pi-extended (hetero)cycles. The coordination preference of the directing group heteroatom determines the chemo- and regio-selectivity of the transformation. This study emphasizes the conceptual development of unsymmetrical multiple annulation of arene C(sp(2))-H bonds with alkynes, which is highly important.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Shenghai Guo, Ziyi Zhang, Yuanqing Zhu, Zhaotong Wei, Xinying Zhang, Xuesen Fan
Summary: A practical and selective method for the synthesis of novel isoquinolone-containing spirocyclic and oxepine-fused polycyclic skeletons through rhodium-catalyzed oxidative [4 + 1] spiroannulation or formal [4 + 3] annulation reactions has been reported. The protocol exhibits wide substrate scope, simple operation procedures, and excellent regioselectivity. The obtained products also hold potential applications in further transformations.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Lukass Lukasevics, Aleksandrs Cizikovs, Liene Grigorjeva
Summary: In this study, we reported a cobalt-catalyzed C-H arylation method using picolinamide as a directing group for phenylalanine derivatives. The reaction displayed good tolerance towards various functional groups and exhibited high yields. The obtained imine products can be easily transformed to 1-aminoisoquinoline derivatives under reductive conditions, providing an attractive alternative. Control experiments suggested that C-H activation might proceed via an electrophilic pathway.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Physical
Qiaoya Zhang, Ci Chen, Bairong Liu, Yuan Liu, Yang Gao, Qian Chen, Yanping Huo, Xianwei Li
Summary: Selective C-H annulation with unsymmetrical alkynes has been a challenge, but recent advances in the development of directing groups, metal catalysts, and versatile alkynes have overcome this problem, ensuring overall regioselectivity, enantioselectivity, efficiency, and synthetic application.
Article
Chemistry, Multidisciplinary
Tamanna Rana, Arijit Ghosh, Yogesh N. N. Aher, Amit B. B. Pawar
Summary: We have developed a redox-neutral synthesis of 3,4-unsubstituted isoquinoline 1(2H)-ones using Cp*Co(III) catalyst and N-chloroamides as starting materials. The reaction is conducted at ambient temperature and utilizes vinyl acetate as a cost-effective and benign acetylene surrogate. The N-Cl bond of the N-chlorobenzamides acts as an internal oxidant, eliminating the need for an external oxidant. The reaction demonstrates broad substrate scope and can also be extended to N-chloroacrylamides, resulting in the formation of 2-pyridone derivatives through vinylic C-H activation.
Article
Chemistry, Multidisciplinary
Palanivelu Gurumurthy, Rajini Raja, Natarajan Arumugam, Abdulrahman I. Almansour, Raju Suresh Kumar, Karthikeyan Perumal, Kanniyappan Parthasarathy
Summary: A Ru(II)-catalyzed C-H annulations of oximes and N-methoxybenzamides with bridged alkyne is reported, which allows for the efficient synthesis of various macrocyclic isoquinolines and isoquinolones in good to moderate yields. A proposed mechanism involves a key five-membered metallacycle intermediate, alkyne insertion followed by reductive elimination to give the annulated product.
Article
Chemistry, Applied
Bairong Liu, Yabo Chen, Qixin Liang, Yuyao Liang, Bifu Liu, Yuan Liu, Yang Gao, Qian Chen, Yanping Huo, Xianwei Li
Summary: Regiodivergent [3+2] and [4+2] C-H annulation of imines and imidate esters with unsymmetrical alkynes has been achieved under Rh(III) catalysis. Further transformation of the aldehyde and TMS functionality on the indene products is also demonstrated. The current work highlights the alcohols-directed multiple C-H annulation of imines and imidate esters, leading to diverse fused heterocycles.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Bing Hu, Guang Chen, Jie Zhao, Lian Xue, Yuqin Jiang, Xinying Zhang, Xuesen Fan
Summary: An effective method for synthesizing succinimide spiro-fused sultams has been developed by coupling N-(phenylsulfonyl)acetamides with maleimides. This cascade reaction features simultaneous annulation and spirocyclization, and uses air as an economical oxidant to assist in regenerating the active Rh(III) catalyst. The new method offers advantages such as readily accessible starting materials, significantly reduced synthetic steps, redox-neutral conditions, high atom-economy, and sustainability.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Organic
Americo J. S. Alves, Nuno G. Alves, Maria I. L. Soares, Teresa M. V. D. Melo
Summary: Spiro-gamma-lactams are a class of spirocyclic compounds found in synthetic bioactive and naturally occurring molecules, with increasing interest in their synthesis as synthetic building blocks in organic chemistry. Recent advances in the synthesis of the spiro-gamma-lactam scaffold since 2015 have addressed issues such as scope, efficiency, selectivity, and mechanistic insights.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Jingxiang Duan, Zongli Xiong, Yuqiao Zhou, Weijun Yao, Xiaoyi Li, Min Zhang, Zhen Wang
Summary: The efficient method reported here successfully synthesizes a range of chiral chromenones with alpha-amino stereogenic centers using quinine-derived squaramide as a promoter. The reaction yields high enantiomeric excess and offers good results in terms of product diversity.
Article
Chemistry, Organic
Majji Shankar, Koushik Ghosh, Kallol Mukherjee, Raja K. Rit, Akhila K. Sahoo
Review
Chemistry, Organic
Raja K. Rit, Majji Shankar, Akhila K. Sahoo
ORGANIC & BIOMOLECULAR CHEMISTRY
(2017)
Article
Chemistry, Organic
Majji Shankar, Tirumaleswararao Guntreddi, E. Ramesh, Akhila K. Sahoo
Article
Chemistry, Organic
Kallol Mukherjee, E. Ramesh, Koushik Ghosh, Akhila K. Sahoo
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2018)
Article
Chemistry, Organic
Koushik Ghosh, Majji Shankar, Raja K. Rit, Gurudutt Dubey, Prasad V. Bharatam, Akhila K. Sahoo
JOURNAL OF ORGANIC CHEMISTRY
(2018)
Article
Chemistry, Organic
Majji Shankar, Koushik Ghosh, Kallol Mukherjee, Raja K. Rit, Akhila K. Sahoo
Article
Chemistry, Organic
Tirumaleswararao Guntreddi, Majji Shankar, Nagarjuna Kommu, Akhila K. Sahoo
JOURNAL OF ORGANIC CHEMISTRY
(2019)
Article
Chemistry, Multidisciplinary
Koushik Ghosh, Raja K. Rit, Majji Shankar, Kallol Mukherjee, Akhila K. Sahoo
Article
Chemistry, Organic
Koushik Ghosh, Arghadip Ghosh, Kallol Mukherjee, Raja K. Rit, Akhila K. Sahoo
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Multidisciplinary Sciences
Kelvin Pak Shing Cheung, Jian Fang, Kallol Mukherjee, Andranik Mihranyan, Vladimir Gevorgyan
Summary: Aliphatic allylic amines are complex and biorelevant molecules that are present in a wide range of compounds. The direct allylic C-H amination of alkenes is the simplest method to obtain these motifs. However, using widely available internal alkenes with aliphatic amines remains a synthetic challenge. We report a general solution to these problems using a blue light-induced open-shell approach and a mild oxidant.
Article
Chemistry, Multidisciplinary
Kallol Mukherjee, Nicolas Grimblat, Somratan Sau, Koushik Ghosh, Majji Shankar, Vincent Gandon, Akhila K. Sahoo
Summary: A direct Pd(ii)-catalyzed kinetic resolution of heteroaryl-enabled sulfoximines through an ortho-C-H alkenylation/arylation of arenes has been developed, providing access to a wide range of enantiomerically enriched unreacted aryl-pyridyl-sulfoximine precursors and C(aryl)-H alkenylation/arylation products in good yields with high enantioselectivity. The coordination of the directing group, ligand effect, geometry constraints, and the transient six-membered concerted-metalation-deprotonation species dictate the stereoselectivity, which is validated by DFT studies.
Article
Chemistry, Multidisciplinary
Majji Shankar, Raja K. Rit, Somratan Sau, Kallol Mukherjee, Vincent Gandon, Akhila K. Sahoo
