Article
Chemistry, Applied
Shubham Debnath, A. Sanjeeva Kumar, Sachin Chauhan, K. C. Kumara Swamy
Summary: Lewis base dependent (3+3) annulations of beta & PRIME;/delta-acetoxy allenoates with iminoindolines can yield alpha-carbolines with varying substituents depending on the base used and reaction conditions. The reaction involves key steps of cyclization, elimination, and trapping. Plausible reaction mechanism has been supported by control experiments and HRMS studies.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Manman Song, Jing Zhao, Er-Qing Li
Summary: This review provides a comprehensive and updated summary of the use of tertiary amine Lewis bases as catalysts for annulation reactions of allenoates. The review highlights diverse reactivities, chemoselectivities, and detailed reaction mechanisms.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Organic
Xue Song, Yangxu Chen, Fangfang Lu, Kai Zhang, Chenxia Yu, Tuanjie Li, Changsheng Yao
Summary: A facile NHC-catalyzed [2 + 4] annulation of allenoates with 2,3-dioxypyrrolidine derivatives has been discovered, providing a new approach for the synthesis of highly substituted pyranopyrrole compounds with moderate to good yields, high atom economy, and mild reaction conditions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Correction
Chemistry, Multidisciplinary
Rick C. Betori, Benjamin R. McDonald, Karl A. Scheidt
Summary: The paper by Rick C. Betori et al. on "Reductive annulations of arylidene malonates with unsaturated electrophiles using photoredox/Lewis acid cooperative catalysis" published in Chem. Sci. in 2019 has been corrected.
Article
Chemistry, Physical
Soojin Kwak, Jeongin Choi, Jimin Han, Sarah Yunmi Lee
Summary: This study presents a Lewis pair-catalyzed process for the selective addition of secondary phosphine oxides to allenoates. Mechanistic studies reveal that the deprotonation of a P-H bond of a SPO by a phosphonium zwitterion is the rate-determining step in the reaction. The reaction proceeds through a catalytic cycle to form alkenylphosphorus building blocks.
Article
Chemistry, Organic
Anton L. Shatsauskas, Ekaterina S. Keyn, Anton J. Stasyuk, Sergey A. Kirnosov, Vladislav Yu. Shuvalov, Anastasia S. Kostyuchenko, Alexander S. Fisyuk
Summary: A new approach for the synthesis of phenanthridin-4-ols and 4-hydroxyphenanthridin-6(5H)-one derivatives was developed. The AlCl3-mediated rearrangement of available 4-phenylbenzo[d]oxazoles and 4-phenyl-1,3-benzoxazol-2(3H)-one yielded the desired products with yields ranging from 43% to 89%. Quantum chemical calculations were utilized to describe the reaction mechanism and predict the thermodynamic parameters.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Dongqiu Li, Fang Cheng, Yuhai Tang, Jing Li, Yang Li, Jiao Jiao, Silong Xu
Summary: In this study, we describe a DABCO-catalyzed [4 + 2] annulation reaction between 5-methylenehex-2-ynedioates and electron-deficient olefins, which leads to the formation of functionalized cyclohexadienes in good yields under mild reaction conditions. The incorporation of the beta- and epsilon-carbons of the substrates for C-C bond formation represents a novel reactivity different from previous reports. It is believed that the annulation proceeds through a domino cyclization initiated by a cross Rauhut-Currier reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nils Ansmann, Deborah Hartmann, Sonja Sailer, Philipp Erdmann, Rezisha Maskey, Marcel Schorpp, Lutz Greb
Summary: In this study, hypercoordinated silicon anions were characterized using a new donor-free polymeric form of Lewis superacidic bis(perchlorocatecholato)silane 1. The results provide insights into the role of silicon hypercoordination in synthesis and catalysis, and suggest pronounced substrate activation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Matthew J. J. Genzink, Matthew D. D. Rossler, Herman Recendiz, Tehshik P. P. Yoon
Summary: Chiral acid catalysts are shown to promote highly selective visible-light photocycloadditions, leading to the synthesis of truxinate natural products. This general approach allows for the efficient synthesis of dimeric and pseudodimeric cyclobutane natural products with excellent enantioselectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Ye Wang, Lei Zheng, Xiaodong Shi, Yunfeng Chen
Summary: In this study, successful 1,3-difunctionalization of beta-alkylsubstituted nitroalkenes was achieved through a synergistic Lewis base catalysis and TBHP radical oxidation, yielding vinylic alkoxyamines in good to excellent yields. This work further extends the general synthetic application of beta-alkyl nitroalkenes.
Article
Chemistry, Multidisciplinary
Minghui Zhu, Peixin Wang, Qinglong Zhang, Wenjun Tang, Weiwei Zi
Summary: The aldol reaction is an important and versatile transformation in organic synthesis, but achieving stereoselectivity for the formation of diastereomeric products is challenging. In this study, a new catalytic system was developed to overcome the selectivity limitations of the reaction. Computational studies provided insights into the reaction mechanism and stereochemistry of the catalytic system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Guguloth Thirupathi, Etikala Ashok, A. Suresh Kumar, Dhevalapally B. Ramachary
Summary: 3-Alkyl-lawsones selectively reacted with alpha-alkyl-nitroethylenes under 500 ppm quinine-NH-thiourea catalysis to produce chiral methanobenzo[7]annulenes with high ee, dr, and TON values. These asymmetric, ppm-level catalytic tandem [3+2]-annulations could inspire the design of more ppm-level organocatalytic reactions, while the final molecules serve as basic skeletons of antibiotics.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Qinyi Li, Xinmin Liu, Weiyu Shi
Summary: This study confirms that the strong electric field and orbital asymmetric hybridization at charged clay surface substantially enhance Lewis acid-base reactions between Cu2+, Ca2+, Mg2+ and surface O. Infrared spectral analyses reveal changes in reaction intensity, highlighting the significance of these factors in clay catalyst design.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Hoimin Jung, Mannkyu Hong, Marianna Marchini, Marco Villa, Philipp S. Steinlandt, Xiaoqiang Huang, Marcel Hemming, Eric Meggers, Paola Ceroni, Jiyong Park, Mu-Hyun Baik
Summary: The mechanism of [2 + 2] cycloadditions activated by visible light and catalyzed by bis-cyclometalated Rh(iii) and Ir(iii) photocatalysts was investigated. Experimental observations show that the Rh-based photocatalyst produces excellent yield and enantioselectivity, whereas the Ir-photocatalyst yields racemates. Two different mechanistic features were found to compete with each other.
Article
Chemistry, Multidisciplinary
Qian Wang, Yinggao Meng, Lulu Wu, Er-Qing Li
Summary: Metal/nucleophilic Lewis base dual catalysis has been recognized as a reliable and promising strategy for finishing ideal organic synthesis. This new strategy expands the synthetic utility of chemical transformations by leveraging additional activation modes and has made considerable progress in the synthesis of a wide range of heterocyclic and biologically active compounds. In this review, the comprehensive and updated advances of metal/nucleophilic Lewis base dual catalytic annulation reactions are described, along with the highlighting of the related mechanism and application in natural product total synthesis.
CHINESE CHEMICAL LETTERS
(2023)
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)
