Article
Chemistry, Organic
Cong-Yun Tang, Jie Wu, Feng-Ting Ji, Fang Tian, Lin Peng, Liang-Liang Wang
Summary: Enantioenriched tricyclic tetrahydropyran derivatives were successfully synthesized through chiral phosphoric acid catalyzed intramolecular reactions, with good yields and excellent stereocontrol. The high enantioselectivity is attributed to the rationally designed remote dual hydrogen bonding interaction, which effectively arranges the conformation of the flexible substrate.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Shaoze Yu, Guosong Shen, Faqian He, Xiaoyu Yang
Summary: A novel method for enantioselective macrocyclization has been developed, which involves chiral phosphoric acid-catalyzed intramolecular addition of the hydroxy group with the allenamide moiety. Planar-chiral macrocycles of various ring sizes and functional groups were generated with good to high enantioselectivities.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Rohan Volpe, Hanson Y-L Law, Jonathan M. White, Bernard L. Flynn
Summary: Directed ortho-lithiation (DoL) is an effective method for the ortho-substitution of BINOL-phosphoric acid and BINOL-N-triflylphosphoramide, allowing for rapid assembly of mono- or disubstituted BINOL-P-acids, including unsymmetrical disubstitution. Most significantly, DoL has proven to be highly effective in the diastereoselective desymmetrization of pseudo-C-2-symmetric BINOL-N-triflylphosphoramide, resulting in a chiral P-group.
Review
Chemistry, Multidisciplinary
Hong-Hao Zhang, Feng Shi
Summary: Catalytic atroposelective synthesis of axially chiral indole derivatives is of considerable importance and has become an emerging focus of research. By designing indole-derived platform molecules and developing strategies for organocatalytic transformations, we have successfully synthesized structurally diversified indole derivatives with axial chirality. These platform molecules possess versatile and unique reactivity, allowing for the synthesis of various axially chiral indole derivatives.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Review
Chemistry, Multidisciplinary
Damien Bouchet, Thomas Varlet, Geraldine Masson
Summary: Enamide and enecarbamate derivatives with nucleophilic and electrophilic centers have dual reactivity, enabling difunctionalization and increased structural complexity. Strategies such as using chiral phosphoric acids and visible-light-promoted atom transfer radical additions have been employed to overcome stability, competititveness, and compatibility issues. The functionalization of these derivatives is a valid synthetic strategy for obtaining important building blocks.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Organic
Xinduo Sun, Chaoji Xiong, Fanrui Zhou, Kun Liang, Chunhua Wu, Xiaoping Rao, Qian Chen
Summary: The asymmetric addition of terminal alkynes catalyzed by a transition metal to isatins is an efficient and economical method for synthesizing 3-alkynyl-3-hydroxy-2-oxindoles. Using a new dimeric chiral quaternary ammonium derived from quinine as the cationic inducer, under mild conditions, the desired chiral compounds can be obtained in good to high yields with high enantioselectivity (<= 99% ee), and a variety of aryl-substituted terminal alkynes and substituted isatins are tolerated in this reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Wengang Guo, Ying Zhou, Hongling Xie, Xin Yue, Feng Jiang, Hai Huang, Zhengyu Han, Jianwei Sun
Summary: In this study, the first metal-free asymmetric H-X bond insertion of its kind was achieved by utilizing visible light as a promoter and a chiral phosphoric acid as a catalyst. Under mild conditions, alpha-diazoesters and aryl amines smoothly underwent N-H bond insertion to form enantioenriched alpha-aminoesters with high efficiency and good enantioselectivity. The key to success was the use of DMSO as an additive, which facilitated the rapid capture of the highly reactive free carbene intermediate to form a domesticated sulfoxonium ylide.
Article
Multidisciplinary Sciences
Min Jin, Congyun Tang, Yingying Li, Shuai Yang, Ying-Tao Yang, Lin Peng, Xiao-Nian Li, Wenjing Zhang, Zhili Zuo, Fabien Gagosz, Liang-Liang Wang
Summary: In this study, the authors present a catalytic asymmetric inverse-electron-demand-hetero-Diels-Alder reaction between neutral alkenes and alpha, beta-unsaturated ketones or aldehydes using a chiral phosphoric acid catalyst. This complex transformation allows for the formation of chiral fused heterocycles containing a central tetrahydropyran ring with high regio-, diastereo- and enantioselectivity. The stereocontrol achieved in this process is attributed to a key remote double hydrogen atom bonding interaction between the linear substrate and the catalyst.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Sun Xinhao, Duan Xuelun, Song Wangze, Jiang Wenfeng
Summary: In this study, diphenyl phosphate was used as a catalyst for the synthesis of sulfoximide-substituted dihydropyranone derivatives with yields ranging from 44% to 78%. The method features mild conditions and good functional group compatibility.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Conor L. Oates, Alister S. Goodfellow, Michael Buehl, Matthew L. Clarke
Summary: A manganese catalyst with a P,N,N ligand that coordinates to the face of the metal catalyzes the hydrogenation of imines derived from indanone derivatives with high enantioselectivity. The generation of imines does not require an activating group and can be done in situ. The selectivity can be explained by DFT calculations.
Review
Chemistry, Multidisciplinary
P. David Bacos, Antti S. K. Lahdenpera, Robert J. J. Phipps
Summary: The Minisci reactions, characterized by the addition of carbon-based radicals to heteroarenes and subsequent rearomatization to form a carbon-carbon bond, have been widely used in medicinal chemistry. This article presents a catalytic strategy using bifunctional Bronsted acid catalysts to achieve regioselectivity and control the stereochemistry in Minisci reactions. The study also includes the development of a predictive model, mechanistic analysis, and synthetic improvements.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Organic
Tao Zhou, Ling-Jie Fan, Zi-Jia Chen, Meng-Xue Jiang, Pu-Fan Qian, Xinquan Hu, Kun Zhang, Bing-Feng Shi
Summary: In this study, we describe the preparation of various structurally diverse P-stereogenic phosphinamides through Pd(II)-catalyzed enantioselective C-H alkynylation using cheap commercially available l-pyroglutamic acid as a chiral ligand. The reactions showed good yields and high enantioselectivities via desymmetrization and kinetic resolution. The presence of a tailor-made congested directing group, N-ethyl-N-(3-methylpyridin-2-yl)amino, was crucial for the reactivity.
Article
Chemistry, Physical
Kaixuan Yang, Ruonan Wang, Dongxue Xu, Xuran Ma, Dairui Ding, Miao Zhang, Liangliang Zhang, Zongxuan Bai, Zhiguo Zhu, Hongying Lu
Summary: In this study, a bifunctional Pd/SiO2-Al2O3-30 catalyst was synthesized for the selective hydrogenation-etherification of furfur-al to furfuryl ether. The incorporation of Si with Al2O3 in the catalysts weakened the metal-support interaction and inhibited the hydrogenation of the furan ring. Meanwhile, the formation of Bronsted acid centers catalyzed the etherification step and promoted the selectivity to corresponding ethers. This work provided an innovative strategy for preparing effective metal-acid bifunctional catalysts for the hydrogenation-etherification of bio-aldehydes to ethers.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Organic
Xiantao Ma, Yingying Zhu, Jing Yu, Ran Yan, Xiaoni Xie, Lijun Huang, Qi Wang, Xue-Ping Chang, Qing Xu
Summary: An unprecedented water oxidation reaction, catalyzed by the thiol cation produced by the Bronsted acid-catalyzed cleavage of a disulfide bond, is observed for the first time. Control reactions and literature support the key transformations in this reaction, and DFT calculation confirms the thermodynamic favorability of the reaction mechanism. This new method provides a transition metal-free, green, and facile synthesis of diverse thioethers.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Viraj A. Bhosale, Ivana Cisarova, Martin Kamlar, Jan Vesely
Summary: This study presents a novel chiral phosphoric acid (CPA)-catalyzed reaction, allowing for the asymmetric addition of alpha-fluoro(phenylsulfonyl)methane (FSM) derivatives to in situ generated cyclic N-acyliminium. The process demonstrates high stereoselectivity, leading to the formation of biorelevant isoindolinones containing sulfone and fluorine substituents with excellent stereoselectivities.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Alexey L. Kaledin, Jose B. Roque, Richmond Sarpong, Djamaladdin G. Musaev
Summary: The study demonstrates a feasible Cu(I)-mediated deconstructive fluorination mechanism for N-benzoylated cyclic amines with Selectfluor (R) through calculations, providing a theoretical basis for the reaction.
TOPICS IN CATALYSIS
(2022)
Review
Chemistry, Multidisciplinary
Vignesh Palani, Melecio A. Perea, Richmond Sarpong
Summary: This review discusses strategies for site-selective functionalization of polyhalogenated arenes and heteroarenes, including traditional reaction types and emerging strategies.
Article
Chemistry, Organic
Melissa A. Hardy, Bozhao Nan, Olaf Wiest, Richmond Sarpong
Summary: Computer-assisted synthesis planning is an emerging research area, particularly for complex molecule synthesis. This study presents a case study on pupukeanane natural products, which are complex, marine-derived compounds with unique tricyclic scaffolds. The authors compare proposed synthesis routes generated using the program SynthiaT with previous syntheses of these molecules and propose novel synthesis routes for previously unprepared pupukeanane congeners.
Article
Chemistry, Multidisciplinary
Robert F. Lusi, Goh Sennari, Richmond Sarpong
Summary: This article describes the synthesis of longiborneol and related natural products. Through clever strategies and late-stage functionalizations, longiborneol and its derivatives were successfully synthesized. The methods employed in this study require extensive optimization but allow for functionalization of every C-H bond in the longiborneol skeleton.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Goh Sennari, Kristen E. Gardner, Stefan Wiesler, Maximilian Haider, Alina Eggert, Richmond Sarpong
Summary: Guided by chemical network analysis, the synthetic studies towards C18- and C19-benzenoid cephalotane-type norditerpenoids were carried out, leading to the construction of core structure in a concise manner and improvement of efficiency through reaction optimization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Christina G. Na, Suh Hyun Kang, Richmond Sarpong
Summary: A C-C bond cleavage/vinylation/Mizoroki-Heck cascade reaction has been developed to access densely functionalized bicyclo[2.2.2]octane frameworks. The method was successfully applied in the total synthesis of 14- and 15-hydroxypatchoulol, providing unambiguous support for their structures and correcting a misassignment in the isolation report.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Correction
Chemistry, Multidisciplinary
G. Logan Bartholomew, Filippo Carpaneto, Richmond Sarpong
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
G. Logan Bartholomew, Filippo Carpaneto, Richmond Sarpong
Summary: A method for the conversion of pyrimidines into pyrazoles has been achieved guided by computational analysis. The method proceeds under mild conditions, with high yields and tolerance to a wide range of functional groups. It enables the regioselective introduction of N-substitution on the resulting pyrazole.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Brandon A. Wright, Anastassia Matviitsuk, Michael J. Black, Pablo Garcia-Reynaga, Luke E. Hanna, Aaron T. Herrmann, Michael K. Ameriks, Richmond Sarpong, Terry P. Lebold
Summary: Azabicyclo[2.1.1]hexanes (aza-BCHs) and bicyclo[1.1.1]pentanes (BCPs) are attractive sp(3)- rich cores for drug scaffolds. Scaffold hopping between these bioisosteric subclasses through a nitrogen-deleting skeletal edit is described. The strategy involves photochemical cycloadditions and subsequent deamination to afford bridge-functionalized BCPs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Daniel Lucke, Alexander S. Campbell, Martin Petzold, Richmond Sarpong
Summary: Here, a synthesis method of 1-hydroxy-2-naphthoic acid esters through an unexpected Lewis-acid-mediated 1,2-acyl shift of oxabenzonorbornadienes is reported. This method allows the obtaining of novel substitution patterns for 1-hydroxy-2-naphtoic acid esters. A mechanistic proposal and rationale for this transformation, which had been previously incorrectly characterized, is provided.
Review
Chemistry, Multidisciplinary
Ian Bakanas, Robert F. Lusi, Stefan Wiesler, Jack Hayward Cooke, Richmond Sarpong
Summary: The oxidation of unactivated C-H bonds has greatly influenced the synthesis of complex molecules, providing more options for starting materials and simplifying the synthesis planning process. This Review classifies and analyzes different types of C-H oxidation reactions based on their strategic purpose and provides case studies to demonstrate their applications in recent total syntheses.
NATURE REVIEWS CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Ian Bakanas, Jess C. Tang, Richmond Sarpong
Summary: This article describes the diversification of tricyclo[3.2.1.0(3,6)]octane scaffolds to synthesize diverse bicyclic scaffolds. The strained tricyclooctanes were prepared in two steps using a blue light-mediated [2+2] cycloaddition. Strategies for the cleavage of this scaffold were then explored, resulting in the selective synthesis of the bicyclo[3.1.1]heptane, bicyclo[3.2.1]octane, and bicyclo[3.2.0]heptane cores. These findings provide a guide for future studies on C-C cleavage reactions in strained carbon frameworks and their application in complex molecule synthesis.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kunlayanee Punjajom, Paul P. Sinclair, Ishika Saha, Mark Seierstad, Michael K. Ameriks, Pablo Garcia-Reynaga, Terry P. Lebold, Richmond Sarpong
Summary: A modular approach to dihydro-1,2,5-thiodiazole dioxide heterocycles is reported. Mechanistic and computational studies support an unusual 1,2 nitrogen migration mechanism for this transformation.
Article
Chemistry, Multidisciplinary
Lucas T. Gottemann, Stefan Wiesler, Richmond Sarpong
Summary: The methoxime group serves as a versatile directing group for various C-H functionalizations. However, converting methoximes to ketones, which is often desired, typically requires harsh reaction conditions. In this study, we propose a mild and functional group tolerant method for the conversion of methoximes to ketones using photoexcited nitroarenes. The utility of this methodology is demonstrated in the total synthesis of cephanolide D, and mechanistic insight is provided through isotope labeling studies and analysis of reaction byproducts.
Article
Chemistry, Multidisciplinary
Karan Goyal, Garrett A. Kukier, Xiangyang Chen, Aneta Turlik, K. N. Houk, Richmond Sarpong
Summary: A novel synthesis method for aryl-substituted, enantioenriched fulvenes from an oxidative Heck cascade and a rearrangement of a carboxy-substituted spiro[4.4]nonatriene is disclosed. Mechanistic investigations using density functional theory (DFT) calculations and empirical results show that the net transformation occurs through a Pd(ii)-mediated 1,5-vinyl shift from a vinyl-palladium intermediate, which terminates with protodepalladation. This method tolerates a range of electron-rich and deficient arylboronic acids and provides moderate to good yields and enantiomeric ratios of mono- and diaryl substituted annulated fulvenes.