Article
Chemistry, Multidisciplinary
Marc Devillard, Nour Nour Eddine, Marie Cordier, Gilles Alcaraz
Summary: A straightforward synthetic methodology for the preparation of photochromic siloles based on the dithienylethene motif has been developed. This method relies on an efficient palladium-catalyzed annulation reaction of a 2,3-bis(3-thienyl)-silirene with terminal alkynes in mild conditions. The reaction is functional group-tolerant and can be extended to the synthesis of photochromic polymers with different degrees of photochromic unit incorporation by adjusting the polymer/silirene stoichiometric ratio.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Feng Zhang, Yujie Niu, Dacheng Hong, Yilin Ye, Yuhui Hua, Shihao Ding, Yandong Zhang
Summary: Atkamine, a complex marine alkaloid, poses a challenging synthesis task for chemists due to its intricate structure. This study presents a synthetic strategy to construct key intermediates of atkamine, including a [5+2] annulation and an asymmetric Michael addition. Successful synthesis of long-chain aliphatic aldehyde and chiral amino acetal fragments was achieved, leading to the construction of a simplified tetracyclic intermediate with the core structure of atkamine.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Organic
Ilya P. Filippov, Mikhail S. Novikov, Alexander F. Khlebnikov, Nikolai V. Rostovskii
Summary: A novel strategy for the synthesis of 1-pyrrolines based on the formal [4 + 1] annulation reaction has been developed in this study. The one-pot approach includes the Rh(II)-catalyzed formation of 4-alkyl-2-azabuta-1,3-dienes, followed by the DBU-promoted cyclization. This method shows good substrate tolerance and can be used to synthesize 1-pyrrolines containing an ester group at the C3 position.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Subaramaniam Thangamalar, Kannupal Srinivasan
Summary: The ring-opening reaction of nitro-substituted donor-acceptor cyclopropanes with pyrazoles in DMSO was investigated. Unexpectedly, the cyclopropanes underwent Kornblum-type ring-opening oxidation with DMSO to form aroylmethylidene malonates as intermediates in the reactions. The intermediates further underwent aza-Michael addition with pyrazoles in tandem manner to give the corresponding aza-Michael adducts. The highlights of the methodology include the occurrence of ring-opening/oxidation under neutral conditions with DMSO and formation of aza-Michael adducts with pyrazoles under catalyst-free conditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yimin Hu, Wangyu Shi, Zhengyang Yan, Jianning Liao, Min Liu, Jiaqing Xu, Wei Wang, Yongjun Wu, Cheng Zhang, Hongchao Guo
Summary: An efficient method using K2CO3 catalysis has been developed for the 1,4-addition/intramolecular cyclization/aromatization reaction of aurone-derived 1-azadienes with trisubstituted allenoates, resulting in a series of benzofuro[3,2-b]pyridines in moderate to excellent yields. The reaction proceeds efficiently under an air atmosphere without the need for transition metal catalysts, providing a concise approach to benzofuro[3,2-b]pyridines.
Article
Chemistry, Organic
Luke R. Odell, Bobo Skillinghaug, Christof Matt, Peng Wu, Tobias Koolmeister, Matthieu Desroses, Sabin Llona-Minguez, Olov Wallner, Thomas Helleday, Martin Scobie
Summary: Here, we describe the development of a new cascade reaction for the synthesis of rare indazole acetic acid scaffolds. By heating 3-amino-3-(2-nitroaryl)propanoic acids with an appropriate nucleophile/solvent under basic conditions, three distinct indazole acetic acid derivatives (unsubstituted, hydroxy, and alkoxy) can be conveniently synthesized. The reaction can tolerate various functional groups and electronic effects, resulting in the synthesis and characterization of 23 novel indazole acetic acids. This work provides a valuable synthetic strategy for drug discovery programs.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jie Wang, Shan-Shan Wang, Jun Xiao, Yu-Jie He, Xin-Yan Wu, Xingguang Li, Pei-Nian Liu
Summary: CF3-substituted imidoyl sulfoxonium ylides (TFISYs) are versatile and powerful synthons for the synthesis of diverse CF3-substituted N-heterocycles, offering broad application prospects.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ruizhi Lai, Shuran Xu, Qingyao Zhang, Hui Zhou, Cankun Luo, Yuerong Wang, Li Hai, Yong Wu
Summary: A method for the synthesis of benzothiadiazine-1,1-dioxide and spiro benzothiadiazine derivatives through transition metal-catalyzed C-H activation/annulation was reported. The reaction substrates used were 3-phenyl-2H-benzothiadiazine-1,1-dioxide, and the coupling reagents used were vinylene carbonate and 4-diazopyrazolone. This strategy provides a straightforward and highly efficient approach to complex N-heterocycles.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Bubul Das, Nikita Chakraborty, Kamal Krishna Rajbongshi, Bhisma K. Patel
Summary: This article reviews different methods and approaches for the synthesis of N/O/S-heterocycles using styrene as an annulating partner in the past five years. These heterocycles are widely present in the core structure of various natural products, pharmaceuticals, and agrochemicals.
Article
Biochemistry & Molecular Biology
Jiaming Wang, Jia Li, Changgui Zhao
Summary: A Lewis acid-promoted annulation method for the synthesis of nitrogen-containing medium-sized rings from azadienes and cyclobutamines has been developed. This reaction involves a cascade of Michael addition and ring-expansion, giving moderate to high yields and a broad scope of products. The use of a chiral base has also been explored for the catalytic asymmetric version of this reaction.
Review
Chemistry, Applied
Feixiang Sun, Erik V. Van Der Eycken, Huangdi Feng
Summary: Oxazolidinone, as a class of important cyclic carbamates, plays a pivotal role in modern organic synthesis and pharmacology. Recent research has focused on their synthesis and ring-opening transformations, aiming to provide researchers opportunities for discovering new reactions.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Xiaoxiang Zhang, Yingying Zhang, Xiaoting Gu, Zhuan Zhang, Wanxing Wei, Taoyuan Liang
Summary: A copper-mediated 2,3-difunctionalization of indoles to afford 3-halogenated 2,3 '-biindoles is described. The protocol uses readily available feedstocks and a naturally abundant copper catalyst system, which allows the regioselective formation of C-C and C-X (X = Cl & Br) bonds in one single operation. Copper metal salt serves not only as a catalyst but also as a reactant to provide the source of halogen, avoiding the use of environmentally unfriendly reagents and displaying good functional group compatibility.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Itaru Suzuki, Kazuki Ogura, Jun-ya Shimazu, Ikuya Shibata
Summary: The MgX2-catalyzed annulation of methylenecyclopropanes with acyl cyanoalkenes resulted in high yields of oxaspiro[2.5]octenes. The rare intramolecular oxa-Michael addition of Mg enolate was found to be the key step in the reaction, with the oxaspiro ring being transformed into 4H-pyran at higher temperatures in the presence of MgX2.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Davit Hayrapetyan, Valeriya Stepanova
Summary: In this study, spirocyclic pyrrolidones and piperidones were synthesized via [3+2]- and [3+3]-aza-annulation reactions starting from readily available alpha-ketolactones and alpha-ketolactams. The annulation reactions proceeded with good yields and excellent diastereoselectivity, creating one C-C and two C-N bonds, as well as three new stereocenters in a fast and efficient manner.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Chemistry, Applied
Yong-Xing Song, Da-Ming Du
Summary: The aza-Michael addition cascade reaction is an important synthetic method for constructing functionalized C-N bonds, widely used in the synthesis of chiral drugs, intermediates, and natural products. This review highlights recent developments in asymmetric synthesis, including various types of aza-Michael addition triggered cascade reactions, reaction mechanisms, and derivatization experiments.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
