Article
Chemistry, Organic
Patricia B. Momo, Eduardo F. Mizobuchi, Radell Echemendia, Isabel Baddeley, Matthew N. Grayson, Antonio C. B. Burtoloso
Summary: Enantioselective sulfa-Michael additions to alpha,beta-unsaturated diazocarbonyl compounds have been developed using quinine-derived squaramide as the catalyst. This method allows the formation of C-S bonds with high stereoselectivity for alkyl and aryl thiols. The synthesis of 22 examples showed enantiomeric ratios up to 97:3 and reaction yields up to 94%. Density functional theory (DFT) calculations were used to determine the mechanism and origins of enantioselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Dmitri Trubitson, Jevgenija Martonova, Marina Kudrjasova, Kristin Erkman, Ivar Jarving, Tonis Kanger
Summary: An efficient enantioselective organocatalytic method has been developed for the synthesis of N-alkylated indoles with alpha-branched alkyl substituents from unsaturated indolyl ketones via a Michael addition. The resulting products exhibit high enantioselectivities and good yields, with tolerance towards various nucleophiles and substitution patterns of the indole ring. Both electron-withdrawing and electron-donating substituents can be accommodated at any position of the heteroaromatic ring.
Article
Chemistry, Multidisciplinary
Daniel Rozsar, Michele Formica, Ken Yamazaki, Trevor A. Hamlin, Darren J. Dixon
Summary: This paper describes a metal-free catalytic intermolecular enantioselective Michael addition to unactivated alpha,beta-unsaturated amides. Consistently high enantiomeric excesses and yields were obtained under mild reaction conditions, using a novel squaramide-based bifunctional iminophosphorane catalyst. Computational analysis revealed the origin of the high enantiofacial selectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Jinhu Wei, Jie-Sheng Huang, Chi-Ming Che
Summary: The chiral Fe-II(N4) complex developed is an effective chiral Lewis acid for the asymmetric conjugate addition of silyl enol ethers to alpha,beta-unsaturated 2-acyl imidazoles, resulting in high yields and enantioselectivities (up to 99% ee) of chiral 1,5-dicarbonyl synthons and cyclohexenone derivatives.
Article
Chemistry, Multidisciplinary
Ding Yuan, Alister S. Goodfellow, Kevin Kasten, Zhuan Duan, Tengfei Kang, David B. Cordes, Aidan P. Mckay, Michael Buhl, Gregory R. Boyce, Andrew D. Smith
Summary: This study demonstrates the enantioselective conjugate addition of carbo- and heterocyclic alpha-substituted beta-ketoesters to alpha,beta-unsaturated aryl esters using HyperBTM as a catalyst. Divergent diastereoselectivity is observed depending on the substituents of the beta-ketoesters, but both cyclopentanone-derived and indanone-derived beta-ketoesters generate desired products with high selectivity.
Article
Chemistry, Multidisciplinary
Daniel Rozsar, Alistair J. M. Farley, Iain McLauchlan, Benjamin D. A. Shennan, Ken Yamazaki, Darren J. Dixon
Summary: This article describes the enantioselective intermolecular conjugate addition of nitroalkanes to unactivated alpha,beta-unsaturated esters catalyzed by a bifunctional iminophosphorane (BIMP) superbase. It provides a straightforward approach to the synthesis of pharmaceutically relevant enantioenriched gamma-nitroesters with unprecedented selectivity. The methodology demonstrates broad substrate scope and has been successfully applied on a gram scale with reduced catalyst loading, allowing for catalyst recovery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Hu Tian, Hong-Ming Zhang, Liang Yin
Summary: In this article, a copper(I)-catalyzed asymmetric conjugate addition/protonation with selenols and alpha-substituted alpha,beta-unsaturated thioamides is described, which produces a series of chiral selenides with high to excellent enantioselectivity. The reaction shows a broad substrate scope for both selenols and alpha-substituted alpha,beta-unsaturated thioamides. The catalytic system is also successfully used for asymmetric selenation of beta-substituted alpha,beta-unsaturated thioamides. A [Cu-(R,R-P)-TANIAPHOS]-SePh species is identified by Se-77 NMR spectra, with a chemical shift at delta 462 ppm. Furthermore, a {[Cu-(R)-TOL-BINAP]-SePh}(2) species is characterized by X-ray analysis, confirming the formation of Cu-Se bond in the reaction. Finally, the straightforward transformations of the thioamide group to amine and thioester are demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Shou-Shan Yang, Ying-Zheng Ren, Yu-Yu Guo, Guang-Fen Du, Zhi-Hua Cai, Lin He
Summary: An organic superbase-catalyzed aminocarbonylation reaction of alpha,beta-unsaturated ketones was reported, leading to the synthesis of alpha-siloxyamides or alpha-hydroxyamides in good yields.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Li Lin, Mei Wang, Jiawei Zhou, Fei Li, Huiyun Liu
Summary: The direct C2 addition of 5H-oxazol-4-ones to gamma-keto-alpha,beta-unsaturated esters catalyzed by a chiral squaramide has been achieved, resulting in diverse highly functionalized gamma-keto esters with a C2-oxazolone at the alpha-position in high yields and excellent stereoselectivities (d.r. > 20:1 and up to 98% ee).
CHEMICAL COMMUNICATIONS
(2023)
Review
Chemistry, Organic
Shuhui Li, Xiaoxuan Li, Hui Yao, Mengting Tan, Dan Xu, Nianyu Huang, Nengzhong Wang
Summary: Straight-chain omega-amino-alpha, beta-unsaturated carbonyl compounds are versatile organic synthons with important applications in organocatalysis. This review discusses the recent applications of these synthons in covalent catalysis, non-covalent catalysis, and bifunctional catalysis.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Jinyi Qian, Hengyuan Zhao, Qi Gao, Lirong Chen, Yinrui Shi, Jiuling Li, Yafei Guo, Baomin Fan
Summary: In this research, a new strategy for the asymmetric carbon-phosphorus bond forming reaction using CBS catalysts via non-covalent interactions was disclosed. Various alpha,beta-unsaturated ketones showed remarkable tolerance to various diarylphosphine oxides, and a new application of oxazaborolidines in enantioselective phospha-Michael addition to alpha,beta-unsaturated ketones under mild reaction conditions was developed.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Jinyi Qian, Hengyuan Zhao, Qi Gao, Lirong Chen, Yinrui Shi, Jiuling Li, Yafei Guo, Baomin Fan
Summary: Classical proline-derived oxazaborolidines, known as CBS catalysts, have significant applications in asymmetric catalysis. This research reveals a new strategy for asymmetric carbon-phosphorus bond formation using CBS catalysts through non-covalent interactions. Various α,β-unsaturated ketones showed excellent tolerance to different diarylphosphine oxides.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Malgorzata Bolt, Kamil Hanek, Patrycja Zak
Summary: A new method utilizing bulky N-heterocyclic carbene (NHC) as a catalyst has been developed for the synthesis of thioesters from enals and thiols. The method has been shown to be effective with a wide substrate scope and high yields above 85% under mild and metal-free conditions. The chemoselectivity of the reaction is significantly influenced by the steric bulk of the NHC carbene ligand.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Jiufeng Wu, Claire M. Young, Amy A. Watts, Alexandra M. Z. Slawin, Gregory R. Boyce, Michael Buhl, Andrew D. Smith
Summary: An enantioselective Michael addition of malonates to alpha,beta-unsaturated para-nitrophenyl esters was successfully achieved using the Lewis basic isothiourea HyperBTM as a catalyst.
Article
Chemistry, Organic
Yoseop Kim, Seung Yeon Kim, Sung-Gon Kim
Summary: A new asymmetric annulation reaction was developed to efficiently synthesize enantioenriched polyheterotricyclic imidazolidines and oxazolidines.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Qi-Kai Kang, Sermadurai Selvakumar, Natarajan Arumugam, Abdulrahman I. Almansour, Raju Suresh Kumar, Keiji Maruoka
CHEMISTRY-AN ASIAN JOURNAL
(2018)
Article
Chemistry, Multidisciplinary
Eric M. Serum, Sermadurai Selvakumar, Nicolas Zimmermann, Mukund P. Sibi
Article
Chemistry, Organic
Qi-Kai Kang, Sermadurai Selvakumar, Keiji Maruoka
Review
Chemistry, Organic
Monika, Sermadurai Selvakumar
SYNTHESIS-STUTTGART
(2019)
Review
Chemistry, Organic
Kalu Ram Bajya, Sermadurai Selvakumar
Summary: Dual photoredox and cobalt catalysis provides a new avenue for transition metal catalyzed cross-coupling reactions. The ability to access low valent cobalt species offers potential for the development of stoichiometric methods.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Deep J. Kalita, Ihor Tarnavchyk, Sermadurai Selvakumar, Bret J. Chisholm, Mukund Sibi, Dean C. Webster
Summary: A novel monomer, 2-eugenoloxy ethyl vinyl ether (EEVE), was synthesized from a renewable bio-based compound, eugenol. The resulting EEVE-based polymers showed improved properties compared to conventional air-drying alkyd resins, such as higher chemical resistance, hardness, glass transition temperature, and Young's modulus. The incorporation of cyclohexyl vinyl ether (CHVE) further enhanced the performance of the crosslinked networks.
PROGRESS IN ORGANIC COATINGS
(2022)
Editorial Material
Chemistry, Organic
Suman K. Saha, Anshul Jain, Akanksha Kumari, Tshering Sangmo Bhutia, Chanchal Agrawat, Nirmal K. Rana
Summary: A simple, mild, and metal-free cascade reaction has been developed for the construction of highly functionalized olefins. The method has a broad substrate scope and allows for substrate recycling.
Article
Chemistry, Applied
Kalu Ram Bajya, Manjeet Kumar, Azaj Ansari, Sermadurai Selvakumar
Summary: Readily available, sterically, and electronically tunable sulfonamides have been developed as effective photoinduced hydrogen atom transfer (HAT) catalysts for selective Si-H functionalizations and hydrogermylation of activated alkenes. N-centered radicals, generated by photoredox catalyzed single-electron oxidation of sulfonamides, serve as key intermediates for silyl and germyl radical generation, enabling the synthesis of organosilicon and organogermanium compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Anshul Jain, Anitta Regina, Akanksha Kumari, Ranjan Patra, Manikandan Paranjothy, Nirmal K. Rana
Summary: Merrifield resin-anchored pyridines were prepared and used as reusable mediators for the trans-selective cascade synthesis of 2,3-dihydroindoles. The method involved the in situ formation of N-ylides followed by Michael substitution reactions. The simple pyridine also efficiently carried out the cascade reaction. The products were further converted into valuable compounds, and the supported pyridine was reused for multiple cycles. Density functional theory calculations confirmed the lower-energy trans-selectivity pathway.
Article
Chemistry, Multidisciplinary
Monika, Kalu Ram K. Bajya, Manoj K. Gupta, Sermadurai Selvakumar
Summary: This study reports the synthesis of 4-aryl-3-bromocoumarin derivatives through in situ generated transient non-symmetric bromoiodanes promoted regioselective intramolecular halocyclization of alkynoates under visible light irradiation. The reaction can be performed using a simple household CFL bulb as a light source without any photocatalyst, leading to moderate to excellent yields of valuable brominated coumarins. Preliminary control studies were also conducted to propose a plausible reaction mechanism.
Article
Chemistry, Organic
Mohammad Sodoor, Sermadurai Selvakumar
Summary: In this study, a facile and efficient method for synthesizing 4-bromoisocoumarins was reported. The method utilized a hypervalent iodine reagent and a bromoiodane catalyst to achieve high yields of various halogenated isocoumarins at room temperature. The reaction exhibited high functional group tolerance and could be scaled up for gram-scale production. The prepared 4-bromoisocoumarins also served as important intermediates for further synthetic transformations.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Organic
Sermadurai Selvakumar
Summary: This review summarizes the recent advances in the field of dual photoredox and chiral hydrogen bonding catalysis in organic transformations. The authors provide a comprehensive overview of the synergistic effects between these two catalytic systems and discuss their mechanistic details and substrate scope.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Akanksha Kumari, Anshul Jain, Khyati Shukla, Ranjan Patra, Nirmal K. Rana
Summary: We have developed a highly stereoselective formal [4 + 1] annulation reaction to construct trans-2,3-dihydrobenzofurans using in situ generated supported pyridinium ylide. This approach shows excellent substrate versatility and the capability of gram-scale synthesis. Moreover, the polymer-anchored pyridine can be recovered and reused multiple times. The product has been transformed into valuable molecules.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Pragati R. Sharma, Apoorva Malik, Sateesh Bandaru, Kanika Vashisth, Nirmal K. Rana, Rakesh K. Sharma
Summary: Lower-rim Cinchona anchored calix[4]arene cationic catalysts were developed for asymmetric Michael addition of acetylacetone to beta-nitrostyrenes. The desired Michael adducts were formed with high yields and enantioselectivities. Density functional theory investigations throw light on the catalyst-substrate interaction and the reaction mechanism.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Anshul Jain, Sushobhan Maji, Khyati Shukla, Akanksha Kumari, Shivani Garg, Ramesh K. Matre, Sudipta Bhattacharyya, Nirmal K. Rana
Summary: A facile method for the synthesis of tri-substituted tetrahydrothiophenes with excellent diastereoselectivity has been developed. The cascade reaction showed broad substrate tolerance and high efficiency, and the synthesized compounds exhibited potential as potent anti-mycobacterial therapeutic leads, as suggested by in silico molecular docking and dynamics simulation analysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
