Article
Chemistry, Applied
Liu-Yang Pu, Fan Yang, Ji-Qiang Chen, Ying Xiong, Jian-Hua Xie, Qi-Lin Zhou
Summary: The enantioselective total synthesis of the pentacyclic proaporphine alkaloid (-)-misramine was achieved, featuring key reactions including Pictet-Spengler cyclization and Baeyer-Villiger oxidation. The absolute configuration of the pentacyclic framework was determined through X-ray single-crystal analyses.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Haiting Yin, Qin Ma, Yushan Wang, Xiaoxia Gu, Zhijun Feng, Yunjun Wu, Ming Wang, Shaoyin Wang
Summary: The study presents a facile and efficient route to tetrahydro-beta-carbolines from 2-indolylmethyl azides and propargylic alcohols via acid-catalyzed dehydrative annulation reactions. The reaction involves a cascade sequence of Friedel-Crafts-type alkylation followed by intramolecular Click reaction, forming multiple chemical bonds in a single operation with excellent atom-economy and broad functional group tolerance.
Article
Chemistry, Organic
Michele Retini, Francesca Bartoccini, Giovanni Zappia, Giovanni Piersanti
Summary: This article describes a new class of chiral thioureas that, in combination with 4-methoxybenzoic acid, promote enantioselective reactions. The formation of a chiral catalyst-anion complex was explored using H-1 NMR spectroscopy.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Qi-Wen Shen, Wei Wen, Qi-Xiang Guo
Summary: The first catalytic asymmetric cascade Heck-alkylation reaction of NH2-unprotected amino acid esters with N-(2-iodophenyl)allenamides is reported in this work. The reaction proceeds smoothly using a combining catalytic system comprising a chiral aldehyde, a chiral palladium complex, and the Lewis acid ZnCl2, giving optically active alpha-alkyl tryptophan derivatives in moderate to good yields and excellent enantioselectivities. The target products can be converted into other structurally complex chiral indoles without the loss of enantioselectivities.
Article
Chemistry, Organic
Fan Xiao, Shi-Ming Xu, Xiu-Qin Dong, Chun-Jiang Wang
Summary: The Ir-catalyzed asymmetric tandem allylation/iso-Pictet-Spengler cyclization reaction provides a direct and practical approach for accessing tetrahydro-gamma-carboline derivatives with multiple functional groups and stereogenic centers in good to high yields and excellent stereoselective control. The wide substrate generality, easily available substrates, and simple chiral catalytic system demonstrate the great potential practicality of this efficient protocol.
Article
Chemistry, Multidisciplinary
Weijian Li, Meifen Jiang, Minjie Liu, Xu Ling, Yingqi Xia, Li Wan, Fener Chen
Summary: This study demonstrates the first fully continuous flow approach towards the asymmetric total synthesis of natural tetrahydroprotoberberine alkaloids. The method features a concise linear sequence without the need for intermediate purification, and involves four chemical transformations and three on-line work-up processing in an integrated flow platform.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Bruna Paes, Andrea R. Aguirre, Bernardo L. Rodrigues, Isolda C. Mendes, Joao Paulo Ataide Martins, Rafael P. Vieira, Heloisa Beraldo
Summary: Attempts to obtain Schiff bases from the reactions of pyridoxal with L-histidine and L-tryptophan resulted in Pictet-Spengler cyclization, leading to the formation of specific cyclic compounds. The diastereoselectivity of the reactions was investigated and the cis isomer was found to be present in both cases. The theoretical calculations of the reactions' free energies and the formation of complexes with zinc indicated the thermodynamic preferences and the prevention of cyclization.
Article
Chemistry, Organic
Meng Wang, Ze-Hong Zheng, Mu-Qiu Chen, Gu Zhan, Jie Wang, Qian-Qian Yang, Wei Huang
Summary: A series of tetrahydro-beta-carbolin 1,3-diketone frameworks can be synthesized efficiently under mild conditions using azlactones and indole-2-amides. This reaction exhibits excellent compatibility and can be completed without a metal mediator.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Applied
Moreshwar B. B. Chaudhari, Prachi Gupta, Patricia Llanes, Miquel A. A. Pericas
Summary: The enantioselective Pictet-Spenlger reaction of tryptamines and diketo compounds catalyzed by a polymer-supported phosphoric acid (TRIP) has been achieved for the first time in continuous flow. A diverse library of quaternary tryptolines has been synthesized in 36-95% yield with 39-99% enantiomeric excess using this approach. The scalability of the reaction has been demonstrated in continuous flow, with a residence time of only 24 minutes. The robust immobilized catalyst has been recycled and reused multiple times in both batch and flow reactions. Synthesis of chiral precursors of Tadalafil, Iboga-type alkaloid (+)-Tabertinggine, and antimalarial spiroindolinones has been successfully achieved in both batch and continuous-flow reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Ahreum Kim, Aram Kim, Sunjung Park, Sangji Kim, Hongil Jo, Kang Min Ok, Sang Kook Lee, Jayoung Song, Yongseok Kwon
Summary: A novel chiral phosphoric acid-catalyzed atroposelective Pictet-Spengler reaction of N-arylindoles has been reported, resulting in highly enantioenriched N-aryl-tetrahydro-beta-carbolines with axial chirality. The introduction of a hydrogen bond donor on the bottom aromatic ring, forming a secondary interaction with the phosphoryl oxygen, is crucial for achieving high enantioselectivity. The transformation is tolerant to a wide variety of substituents and can provide products with up to 98% ee.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Marek Buchman, Elliot P. Farney, Stephen N. Greszler, Robert J. Altenbach, Gregory A. Gfesser, Eric A. Voight
Summary: This study presents operationally facile methods for synthesizing substituted dihydroisoquinolinones and tetrahydroisoquinolines from readily accessible substrates. Cyclized products as single regioisomers are efficiently produced from electronically diverse substrates, demonstrating a departure from traditional methods tailored to electron-rich precursors.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Eun Ji Bang, Jongmin Ra, Hoe Young Choi, Haye Min Ko
Summary: An efficient synthetic approach involving indole alkylation/Pictet-Spengler cyclization has been developed to form benzazepinoindole derivatives. The reaction is operationally simple and tolerates various functional groups, providing a direct route to access benzazepinoindole-containing natural products and bioactive compounds.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Gourishetty Srikanth, Anil Ravi, Anusha Sebastian, Jobi Joseph, Monther A. Khanfar, Mohammed I. El-Gamal, Raed A. Al-Qawasmeh, Ihsan A. Shehadi, Scott McN. Sieburth, Imad A. Abu-Yousef, Amin F. Majdalawieh, Taleb H. Al-Tel
Summary: A new class of pseudo-NP collection was developed by connecting tryptamines with a furanose derivative and subjecting the product to a ring distortion strategy. This led to diastereoselective synthesis of camptothecin-like compounds through a cascade of Pictet-Spengler reaction, Michael addition reaction, oxidative-ring enlargement, and transannular aldol cyclization. The obtained diastereoselectivity was verified using density functional theory (DFT) calculations.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Vidhi Patel, Tushar Bambharoliya, Drashti Shah, Yug Patel, Neel Savaliya, Yash Patel, Riddhisiddhi Patel, Vashisth Bhavsar, Harnisha Patel, Mehul Patel, Ashish Patel
Summary: The beta-Carboline and its derivatives are privileged heterocyclic motifs and important building blocks in medicinal chemistry. Their wide range of biological activities has attracted great interest. Many synthetic methods have been developed to address the challenges of synthesizing beta-Carboline framework. This review presents the research work reported in recent scientific literature focusing on different synthetic methods of beta-Carboline and related derivatives.
POLYCYCLIC AROMATIC COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Wen-Duo Li, Jie Chen, Dao-Yong Zhu, Ji-Bao Xia
Summary: This study introduces a novel cyclization reaction using CO2 as a sustainable C1 feedstock and iron as catalyst, achieving selective reduction into methylene intermediate under carefully tuned reaction parameters. Various nitrogen-containing heterocycles can be easily obtained under mild conditions, possibly via spiroindolenine intermediates.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
C. Rose Kennedy, Dan Lehnherr, Naomi S. Rajapaksa, David D. Ford, Yongho Park, Eric N. Jacobsen
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2016)
Article
Chemistry, Multidisciplinary
David D. Ford, Dan Lehnherr, C. Rose Kennedy, Eric N. Jacobsen
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2016)
Article
Chemistry, Organic
Dan Lehnherr, David D. Ford, Andrew J. Bendelsmith, C. Rose Kennedy, Eric N. Jacobsen
Article
Chemistry, Multidisciplinary
Valerie A. Schmidt, C. Rose Kennedy, Mate J. Bezdek, Paul J. Chirik
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2018)
Article
Chemistry, Multidisciplinary
C. Rose Kennedy, Hongyu Zhong, Rachel L. Macaulay, Paul J. Chirik
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2019)
Article
Chemistry, Applied
C. Rose Kennedy, Hongyu Zhong, Matthew V. Joannou, Paul J. Chirik
ADVANCED SYNTHESIS & CATALYSIS
(2020)
Article
Chemistry, Multidisciplinary
C. Rose Kennedy, Bo Young Choi, Mary-Grace R. Reeves, Eric N. Jacobsen
ISRAEL JOURNAL OF CHEMISTRY
(2020)
Article
Chemistry, Multidisciplinary
Megan Mohadjer Beromi, C. Rose Kennedy, Jarod M. Younker, Alex E. Carpenter, Sarah J. Mattler, Joseph A. Throckmorton, Paul J. Chirik
Summary: The study describes a method of [2+2] cycloaddition/oligomerization of 1,3-butadiene to produce a thermally stable material with high crystallinity, demonstrating the potential of closed-loop chemical recycling.
Article
Chemistry, Physical
C. Rose Kennedy, Matthew Joannou, Janelle E. Steves, Jordan M. Hoyt, Carli B. Kovel, Paul J. Chirik
Summary: This study describes the selective intermolecular homodimerization and cross-cycloaddition of vinylsilanes with unbiased 1,3-dienes catalyzed by a pyridine-2,6-diimine (PDI) iron complex. The chemoselectivity of these reactions was found to be distinct from that of similar alpha-olefin reactions with 1,3-dienes. Mechanistic studies provided insights into substrate-controlled regioselectivity, and identified diamagnetic iron diene and paramagnetic iron olefin complexes as catalyst resting states. The relative rates of beta-H elimination and C-C reductive elimination were ultimately governed by the silyl substituents, dictating final product formation.
Article
Chemistry, Inorganic & Nuclear
Medina Afandiyeva, Abhishek A. Kadam, Xijue Wu, William W. Brennessel, C. Rose Kennedy
Summary: This paper describes a family of anionic, formally nickel(0) complexes supported by bidentate NHC-pyridone ligands. These complexes have an unsymmetric chelating environment and a capping [K(18-crown-6)]+ countercation, allowing for isolation of single-component, monometallic complexes in high yield. The steric and electronic properties are evaluated using experimental (NMR, IR, UV-vis, X-ray diffraction) and computational tools. Catalytic activity for highly branched-selective hydroboration of styrene with HBpin is demonstrated. Control experiments suggest that the pyridone plays an important role in establishing reactivity and regioselectivity, indicating the potential to utilize secondary coordination sphere effects for reagent activation and delivery with these single-component precatalysts.
Article
Chemistry, Organic
Dalton J. Hanaway, C. Rose Kennedy
Summary: Recent theoretical work and experiments have provided a strong conceptualization for the effects of oriented electric fields (OEFs) on organic reactions. However, evaluating reaction sensitivity to field effects has been inefficient in practice. This study presents the development of an automated tool, A.V.E.D.A, for efficient evaluation of a reaction's susceptibility to OEFs.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Editorial Material
Chemistry, Multidisciplinary
Abhishek A. Kadam, C. Rose Kennedy
Summary: Recently, the Chu/Szymczak and Drover groups independently reported the synthesis and characterization of nickel(0) complexes with distinct boron-containing bisphosphines. These complexes were used for elegant secondary-sphere activation of Lewis basic substrates: organoazides and nitriles. The reports provide insights into strategies for secondary-coordination-sphere activation and highlight areas for further innovation.
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Sarah M. Craig, Kaycie R. Malyk, Elliot S. Silk, Daniel T. Nakamura, William W. Brennessel, C. Rose Kennedy
Summary: In the past decade, N-heterocyclic carbene, bipyridine, and pyridine oxazoline ligands have been increasingly used in nickel catalysis. The combination of a low-oxidation-state 3d metal and an electron-rich ligand allows for challenging bond activations. This study reports the synthesis and characterization of two Ni(0) complexes supported by a novel bidentate C,N ligand, (h)IMesPy, which shows potential for overcoming reactivity challenges.
JOURNAL OF COORDINATION CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Kyle E. Rosenkoetter, C. Rose Kennedy, Paul J. Chirik, Benjamin G. Harvey