Article
Chemistry, Organic
Zhenming Zhang, Bei Fu, Xiaoshuo Wang, Zhipeng Hu, Xuanling Liu, Tao Wang, Junfeng Zhao
Summary: An efficient and general base-promoted reaction for the synthesis of (Z)-beta-chloro-enamides using 1,1-dichloroalkenes and secondary sulfonamides or amides has been described. This reaction exhibits excellent functional group tolerance under simple and mild conditions. Mechanistic study suggests that the stereoselective trans-hydroamidation of alkynyl chlorides generated in situ from 1,1-dichloroalkenes is the key step.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Xiang Lyu, Jianbo Zhang, Dongwook Kim, Sangwon Seo, Sukbok Chang
Summary: A NiH-catalyzed strategy for the hydroamidation of alkynes with dioxazolones has been reported in this study, providing synthetically useful secondary enamides in (E)-anti-Markovnikov or Markovnikov selectivity. The reaction is viable for various alkynes and functional groups, with H2O found to be essential for high catalyst turnovers. Inner-sphere nitrenoid transfer is proposed as a key component in outcompeting undesired processes in the Ni catalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Yang Yuan, Fengqian Zhao, Xiao-Feng Wu
Summary: This study introduces a copper-catalyzed enantioselective hydroaminocarbonylation method for constructing alpha-chiral secondary amides. The method shows high yields and high levels of enantioselectivity under very mild conditions. Additionally, alpha,beta-Unsaturated secondary amides can be produced by using alkynes as the substrate.
Article
Chemistry, Organic
Lingfei Hu, Han Gao, Yanlei Hu, Xiangying Lv, Yan-Bo Wu, Gang Lu
Summary: DFT calculations and EDA were used to investigate the mechanism and origin of ligand effects on stereoinversion in Pd-catalyzed synthesis of tetrasubstituted olefins. It was found that the steric properties of the ligands lead to different stereoselectivity-determining steps, with Pauli repulsion and polarization playing dominant roles in controlling stereochemistry in 1,2- and 1,3-migrations, respectively. Differences in Pauli repulsion and polarization between the two stereoselective transition states were further identified.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Wenlong Ren, Mingzhou Wang, Jianqiong Guo, Jintao Zhou, Jianxiao Chu, Yuan Shi, Yian Shi
Summary: A regioselective Pd-catalyzed hydrocarboxylation of terminal olefins with HCOOH is described. A wide variety of branched carboxylic acids can be obtained easily under mild reaction conditions with high regioselectivities. The operation of the reaction is simple and does not require handling toxic CO. The ligand and LiCl play important roles in reaction reactivity and selectivity.
Article
Multidisciplinary Sciences
Yao Zhang, Deyong Qiao, Mei Duan, You Wang, Shaolin Zhu
Summary: In this study, a new synthetic method was reported for the highly enantioselective synthesis of chiral alpha-aminoboronates and their derivatives under mild conditions. The method was demonstrated to be efficient for the synthesis of a current pharmaceutical agent.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Xianjun Xu, Liliang Huang, Eva Smits, Ling Zhong, Huangdi Feng, Erik V. Van der Eycken
Summary: A novel strategy for the synthesis of various N-alkenylisoquinolinones is reported, featuring broad functional group tolerance and good chemoselectivity. This strategy involves sequential palladium-catalyzed cyclization and C-4-O bond cleavage of oxazolidines to form carbon-carbon and carbon-oxygen double bonds. Additionally, the practical value of this method is explored by conducting a millimole reaction and utilizing palladium-catalyzed C-H arylation and visible-light-assisted photocatalyzed conversion of the cyclic enamide to valuable compounds.
NEW JOURNAL OF CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Zhikun Zhang, Srikrishna Bera, Chao Fan, Xile Hu
Summary: This article summarizes the importance of compounds rich in sp(3)-hybridized carbons in drug discovery, and introduces the nickel-catalyzed hydrocarbonation of alkenes as a potentially efficient method to synthesize these compounds. The article focuses on enantioselective reactions and provides a critical discussion of the state and challenges of the field.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Xiao-Xia Ming, Shuai Wu, Ze-Yu Tian, Jia-Wei Song, Cheng-Pan Zhang
Summary: The study confirmed the potential of (2-bromoethyl)diphenylsulfonium triflate as a powerful vinylation reagent in Sonogashira cross-coupling reactions. The vinylation proceeded smoothly at 25 degrees C under Pd/Cu catalysis, yielding a variety of 1- and 2-unsubstituted 1,3-enynes in moderate to excellent yields. This protocol represents the first application of (2-haloethyl)diphenylsulfonium triflate as a CH=CH2 transfer source in organic synthesis.
Article
Chemistry, Physical
Feng Wang, Yuecong Guo, Yutong Zhang, Pingping Tang
Summary: The silver-catalyzed dibromotrifluoromethoxylation of terminal alkynes reported provides 1,1-dibromo-2-(trifluoromethoxy)alkenes in good yields and high regioselectivity under mild reaction conditions. The reaction has a broad substrate scope and can be used for late-stage trifluoromethoxylation of complex small molecules. The products can be further modified, offering a convenient method for synthesizing compounds containing the OCF3 group.
Article
Chemistry, Physical
Qiang Huang, Yu-Xuan Su, Wei Sun, Meng-Yang Hu, Wei-Na Wang, Shou-Fei Zhu
Summary: In this study, an operationally simple and mild iron-catalyzed alkylzincation method for terminal alkynes was developed, which can efficiently produce diverse alkenylzinc compounds with high selectivity. The method demonstrates a high anti-Markovnikov selectivity and high cis stereoselectivity, making it a competitive alternative for the selective synthesis of trisubstituted olefins.
Article
Chemistry, Organic
Peizhi Bai, Yubo Jiang, Tiebo Xiao, Guiping Qin
Summary: A Pd-catalyzed cascade reaction has been reported for the efficient construction of stereodefined skipped trienes under mild reaction conditions in a single-step. The reaction tolerates a variety of functional groups and provides substituted stereodefined skipped trienes in moderate to good yields. Preliminary mechanism investigations suggest that the Sonogashira reaction and radical pathway may not be involved in this novel multicomponent coupling reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Aleksandra Blocka, Wojciech Chaladaj
Summary: We report a new method for the synthesis of highly substituted vinylidenecyclopentanes with good yields, complete selectivity, and excellent functional group tolerance. The mechanism involves the oxidative addition of bromoarene to Pd(0), followed by cyclization and reductive elimination. The high regio- and stereoselectivity can be attributed to the 5-exo-dig intramolecular addition of the enol form of the substrate to alkyne activated by the pi-acidic Pd(II) center.
Article
Chemistry, Organic
Juntao Yang, Bingxian Liu, Junbiao Chang
Summary: A ruthenium(II)-catalyzed one-pot synthesis of highly substituted 1,2-dihydropyridines (DHPs) via a three component reaction system has been successfully developed. The reaction utilizes a simple Ru(II) catalyst without the need for specific ligands. The catalytic system shows excellent functional group compatibility with a wide range of starting materials. The obtained DHPs can be easily converted into tetrahydropyridines and azabicyclo[4.2.0]octa-4,7-dienes by subsequent reduction or [2 + 2] cycloaddition reaction.
Article
Multidisciplinary Sciences
Yun-Nian Yin, Rui-Qi Ding, Dong-Chen Ouyang, Qing Zhang, Rong Zhu
Summary: The authors have developed a single-step approach for the synthesis of α-tertiary amides via cobalt-catalyzed intermolecular oxidative hydroamidation of unactivated alkenes. This method shows good selectivity for terminal alkenes and avoids competing reactions with other functional groups, providing a straightforward access to a diverse array of hindered amides.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Subhadra Ojha, Niranjan Panda
ADVANCED SYNTHESIS & CATALYSIS
(2020)
Correction
Chemistry, Applied
Subhadra Ojha, Niranjan Panda
ADVANCED SYNTHESIS & CATALYSIS
(2020)
Article
Chemistry, Organic
Subhadra Ojha, Niranjan Panda
Summary: This method utilizes palladium catalysis to synthesize diaryl sulfones from arenes, using N-methoxy arenesulfonamide as a sulfonyl donor, with advantages such as a simple and readily available catalytic system, stable sulfonyl donor, and tolerances of aryl bromides and iodides for further cross-coupling reactions to produce cross-coupled sulfones.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Priyadarshini Mishra, Nayim Sepay, Niranjan Panda
Summary: A silver-catalyzed aerobic approach has been developed for the synthesis of 2-methyl-chromone-3-carboxylic acid from the reaction of 4-hydroxy coumarin and enol ester in the presence of base. Mechanistic investigation suggests that the key steps for the overall transformation include the base induced Michael-type addition reaction and sequential ring opening and closing with the liberation of acetone. Theoretical calculation of energy of the intermediates by DFT supports the proposed reaction mechanism.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Applied
Kanchanbala Sahoo, Niranjan Panda
Summary: Iron(III) chloride mediated reactions were used to synthesize chlorinated benzoxazoles selectively at the para position of the substrate. Additionally, the oxidative cross-dehydrogenative coupling of amidophenol with anisole using ferric chloride allowed for the synthesis of remotely anisylated benzoxazoles.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Pallaba Ganjan Dalai, Kuntal Palit, Niranjan Panda
Summary: A method to generate halogen cation pools from the reaction of 1,2-dihaloethanes and dimethyl sulfoxide for C-H halogenation of arenes and heteroarenes was reported. This protocol demonstrates synthetic utility in pharmaceutical chemistry.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Subhadra Ojha, Niranjan Panda
Summary: A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. The reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Sujit Maity, Sandip Kumar Gupta, Niranjan Panda
Summary: The study focused on the direct oxidative coupling of vicinal diols with 2-aminonaphthoquinones for the selective synthesis of benzo[f]indole-4,9-diones at a moderate temperature. The environmentally benign iron catalyst was found to effectively oxidize the vicinal diols to alpha-hydroxy carbonyl compounds, resulting in a vast range of pyrrolonaphthoquinones in remarkable yield. Interestingly, the use of 1,2-propanediol led to the selective oxidation of the secondary alcohol group, producing 2-methyl pyrrolonaphthoquinones as the major regioisomer.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Priyadarshini Mishra, Niranjan Panda
Summary: A silver salt-mediated aerobic approach has been developed for the synthesis of 4-acetyl 3-unsubstituted isocoumarins. The reaction involves the cleavage of enol ester mediated by a base followed by silver-mediated C-arylation. Intramolecular annulation and dehydration lead to the formation of 4-acyl isocoumarins. Selective demethylation and reduction followed by demethylation provide access to biologically potent AGI-7 and sescandelin in good yield.
Article
Chemistry, Applied
Pallaba Ganjan Dalai, Niranjan Panda
Summary: The benzannulation and N-annulation of beta-ketoenamines using the in-situ generated methyl(methylene)sulfonium ion from the reaction of DMSO and DBE was achieved. This reaction provides a novel method for synthesizing pyridine derivatives and substituted anilines.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Kuntal Palit, Nayim Sepay, Niranjan Panda
Summary: A divergent synthesis of alpha-C-H methylated pyrazines and pyrazinones was achieved using dimethyl sulfoxide as a nonconventional methylating agent under metal-free conditions. The dimethyl sulfoxide-coordinated bromine cation pools generated from the treatment of dimethyl sulfoxide and 1,2-dibromoethane underwent Pummerer-type fragmentation, leading to the formation of an electrophilic methyl(methylene)sulfonium ion. This ion reacted with a carbon nucleophile and subsequent aromatization afforded alpha-methylated pyrazines and pyrazinones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Sandip Kumar Gupta, Niranjan Panda
Summary: A Pd(II)-catalyzed dehydrogenative remote C4-H coupling of indoles with unfunctionalized arenes at room temperature was achieved using a weak chelating trifluoroacetyl group as a directing group. Various substituents on the arenes were compatible with the dehydrogenative cross coupling reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Pallaba Ganjan Dalai, Swayamprava Swain, Soumya Mohapatra, Niranjan Panda
Summary: A metal-free direct sulfamidation of 1,4-naphthoquinones using N-methoxy sulfonamides in water was developed. The base-mediated nucleophilic addition of N-methoxy sulfonamides, followed by N-O bond cleavage, allowed the synthesis of enesulfonamides. The practicality of this approach was further demonstrated by the synthesis of pyrrolonaphthoquinones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Kanchanbala Sahoo, Priyanka Pradhan, Niranjan Panda
ORGANIC & BIOMOLECULAR CHEMISTRY
(2020)
Correction
Chemistry, Organic
Niranjan Panda, Irshad Mattan, Subhadra Ojha, Chandra Shekhar Purohit
ORGANIC & BIOMOLECULAR CHEMISTRY
(2019)
