Article
Chemistry, Multidisciplinary
Heng-Zhi Tian, Qing-Gang Tang, Guo-Qiang Lin, Xing-Wen Sun
Summary: A novel approach to synthesize chiral 1,2-oxazinane spirocyclic scaffolds by organocatalytic [4 + 2] cycloaddition reaction has been developed. In addition, a hydrazide 1,4-synthon is synthesized to construct chiral hexahydropyridazin spirocyclic scaffolds. Both reactions exhibit good to excellent yield, diastereoselectivity, and enantioselectivity.
Article
Chemistry, Organic
Gary L. Points, Christopher M. Beaudry
Summary: Substituted carbazoles are efficiently synthesized from 3-triflato-2-pyrones and alkynyl anilines, allowing for multiple substituents with complete control of regiochemistry, resulting in complex substitution patterns. This strategy can also be applied to prepare substituted bicarbazoles and related biaryls, and has been demonstrated in the synthesis of the carbazole natural product clausine C.
Article
Chemistry, Organic
Kseniya A. Alekseeva, Maryana A. Nadirova, Vladimir P. Zaytsev, Evgeniya V. Nikitina, Mikhail S. Grigoriev, Anton P. Novikov, Irina A. Kolesnik, Bernhard Mayer, Thomas J. J. Mueller, Fedor I. Zubkov
Summary: Diversely substituted, partially saturated benzo-[f]-isoindole-4-carboxylic acids were synthesized through a new three-component reaction. The reaction showed high regio- and stereoselectivity, resulting in the formation of a chiral center and a diastereoisomer.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Qi Xue, Ren Wang, Wen-Yu Zhang, Fang-Fang Shen, Yang Li, Qing Sun, Jin-Heng Li
Summary: A new palladium-catalyzed multicomponent dearomatization of arylamines with CO and propargylic acetates for the synthesis of bridged polycyclic lactams is reported. This method enables double annulation at the ipso and para positions of the amino group, leading to the formation of four new bonds, including three C-C bonds and one C-N bond. DFT calculations and experimental studies suggest that the efficient formation of the allenecarboxanilide intermediate is crucial for the dearomative transformation.
Article
Chemistry, Multidisciplinary
Thomas Varlet, Mateja Matisic, Elsa Van Elslande, Luc Neuville, Vincent Gandon, Geraldine Masson
Summary: A diastereodivergent and enantioselective synthesis of chiral spirocyclohexyl-indolenines with four contiguous stereo-genic centers was achieved through a chiral phosphoric acid-catalyzed cycloaddition. By carefully choosing reaction conditions, modular access to two different diastereoisomers with high enantioselectivities was obtained. The functional group manipulation of these compounds provides an efficient access to enantioenriched spirocyclohexyl-indolines and -oxindoles.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Yan Jiang, Hao-Jie Ma, Xue-Long Wang, Yi Yang
Summary: A Yb(OTf)(3)-catalyzed formal (4 + 3) cycloaddition reaction was successfully achieved using donor-acceptor cyclopropanes and 3-benzylideneindoline-2-thiones as reactants. Functionalized 5,10-dihydro-2H-thiepino[2,3-b]indole derivatives were synthesized with good yields and moderate to good diastereoselectivity. This reaction represents the first (4 + 3) cycloaddition of 3-benzylideneindoline-2-thiones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Takayuki Iwata, Mitsuru Shindo
Summary: This paper summarizes the syntheses of 1,8,13-substituted triptycenes, highlighting the interesting structural features of their C-1,8,13 substituents and the open faces of the molecule for various interactions and applications.
Article
Chemistry, Applied
Wei-Yang Ma, Emeric Montinho-Inacio, Bogdan I. Iorga, Pascal Retailleau, Xavier Moreau, Luc Neuville, Geraldine Masson
Summary: This study describes an enantioselective chiral phosphoric acid catalyzed formal [4 + 2] cycloaddition reaction between 2-benzothiazolimines and N-H-1,3-dienecarbamates. The reaction pathways diverge depending on the dienes employed, leading to different reaction products and enantioselectivities.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Sloan Ayers, Gregory L. Beutner, Wei Ding, Carolyn Higman, Charles Pathirana, Robert Wethman
Summary: Having reliable methods to monitor catalyst activation processes is crucial for ensuring the reproducibility of catalytic reactions. For asymmetric Diels-Alder reactions, chiral oxazaborolidine or oxazaborolidinium catalysts are powerful reagents that promote these reactions with high yield and selectivity. By investigating the mechanism, several modern analytical methods are compared to quantitate the formation of oxazaborolidine catalyst from amino alcohol and boroxine, leading to useful monitoring methods for this important transformation.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Review
Chemistry, Organic
Ghanshyam Mali, Amar Nath Singh Chauhan, Kailas Arjun Chavan, Rohan D. Erande
Summary: The class of Double Diels-Alder (DDA) reactions leads to targets succinctly with conceptually novel and streamlined methods. This growing branch of Diels-Alder reactions triggers the streamlined construction of polycyclic and macrocyclic architectures. The emphasis is on the synthesis of various structural classes based on the selectivity of the DDA reaction.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Thomas Varlet, Geraldine Masson
Summary: Chiral substituted cyclic amines are important in organic synthesis, with stable and easy to synthesize enamides and dienamides serving as versatile building blocks for the preparation of chiral amines. The exceptional synergy between these synthetic synthons and chiral phosphoric acid catalysts has been successfully utilized to develop formal cycloadditions with high enantioselectivity, allowing access to chiral cyclic amines with varying ring sizes.
CHEMICAL COMMUNICATIONS
(2021)
Article
Polymer Science
Daniela Ionita, Mariana Cristea, Constantin Gaina, Mihaela Silion, Bogdan C. Simionescu
Summary: This study reveals the retroDA reaction of anthracene-maleimide Diels-Alder adduct in anthracene modified polyester resins through thermal analysis. At high temperatures, maleimide homopolymerizes and reacts with allyl groups, resulting in the absence of thermal DA reaction.
Article
Chemistry, Multidisciplinary
Marlene Fadel, Erick M. Carreira
Summary: The first total synthesis of (+)-pedrolide, a tigliane-derived diterpenoid featuring an unprecedented 5-5-6-6-3 carbon skeleton, was achieved. A key step in the synthesis involved the construction of the bicyclo[2.2.1]heptane core via an intramolecular cyclopentadiene-Diels-Alder cycloaddition. A norbornadiene was used as a surrogate for cyclopentadiene, and the unmasking of the cyclopentadiene was achieved through a complex Diels-Alder reaction cascade. This synthesis also provided a novel approach to a densely functionalized carane in an efficient and enantioselective manner.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemistry & Molecular Biology
R. Alan Aitken, Lynn A. A. Power, Alexandra M. Z. Slawin
Summary: (2S,5S)-5-Phenyl-2-t-butyl-1,3-dioxolan-4-one, derived from mandelic acid, can undergo Michael addition reactions with butenolide and 4-methoxy-beta-nitrostyrene, with the absolute configuration of the products confirmed by X-ray diffraction. Thermal fragmentation of the dioxolanone in these reactions results in the formation of phenyl ketone and chiral epoxy ketone, demonstrating its role as a chiral benzoyl anion equivalent and chiral ketene equivalent, respectively. Additionally, the Diels-Alder cycloaddition chemistry of (2S)-5-methylene-2-t-butyl-1,3-dioxolan-4-one, derived from lactic acid, has been studied, and the X-ray structures of four adducts have been determined, providing insights into the mechanism of dioxolanone fragmentation.
Review
Chemistry, Organic
Alemayehu Gashaw Woldegiorgis, Muhammad Suleman, Xufeng Lin
Summary: Asymmetric cycloaddition/annulation reactions have played a significant role in the synthesis of novel cyclic compounds for organic synthesis, natural product synthesis, material science, and chemical biology. Chiral phosphoric acid-catalyzed reactions have attracted attention in the synthetic community for the past two decades to develop new asymmetric reactions and synthesize complex molecules.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
