Article
Chemistry, Multidisciplinary
Bao-Cheng Wang, Li Rao, Kai-Xin Fang, Bao-Le Qu, Fen-Ya Xiong, Ying Feng, Ying Tan, Liang-Qiu Lu, Wen-Jing Xiao
Summary: Metal-polarized aza-ortho-quinone methides (aza-o-QMs) have been effectively utilized in azaheterocycle synthesis, and a new reaction mode involving transient dearomatized spiroaziridine intermediates has been discovered. This has led to the efficient and flexible divergent synthesis of bis-nitrogen heterocycles through sequential dearomatization-rearomatization reactions. Experimental, theoretical, and cellular evaluations have been conducted to explain the mechanisms, selectivity, and potential medicinal applications of the synthesized compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Santosh J. Gharpure, Santosh K. Nanda, Dipak J. Fartade
Summary: This study demonstrates a facile synthesis of 1,4-heterocycle-fused quinoline motifs through intramolecular formal [4+2]-cycloaddition, involving tandem bond formation reactions and showing excellent functional group tolerance, leading to the synthesis of enantiomerically enriched compounds. Additionally, sulfoxide embedded quinolines were successfully transformed into pentacyclic 1,4-thiepino tethered indeno-quinoline scaffolds via Pummerer cyclization.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Yuan Chen, Rui Yu, Min Wang, Yanmin Huang, Yungui Peng
Summary: An asymmetric 1,6-conjugate addition reaction of dialkyl diazomethylphosphonates to para-quinone methides was developed using phase-transfer catalysis, yielding chiral diarylmethylated diazomethylphosphonates with high yields and enantioselectivities. The resulting products were further transformed into bioactive compounds with diarylmethine stereogenic centers.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Review
Chemistry, Physical
Mercedes Zurro, Aitor Maestro
Summary: This paper reviews the recent literature on the catalytic methodologies for the derivatization of aza-QM, including organocatalytic and organometallic approaches. The review analyzes various catalytic systems, involving chiral NHC carbenes, phosphoric acids, phosphoramidites, phosphine, copper, and palladium catalysis, showcasing their applicability for the synthesis of a diverse array of N-containing compounds, many of which exhibit biological activity.
Article
Chemistry, Multidisciplinary
Xingxing Wu, Christof Sparr
Summary: This paper describes the feasibility of an intramolecular Friedel-Crafts 6 pi electrocyclization, which is stereocontrolled by contact ion pairs. Through the use of a disulfonimide catalyst, enantioenriched acridinium tetrafluoroborate salts can be selectively synthesized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Fabian Hofmann, Cornelius Gaertner, Martin Kretzschmar, Christoph Schneider
Summary: Aza-Diels-Alder reactions are direct processes for constructing N-heterocycles, with inherent atom economy and stereospecificity. Intramolecular strategies can form bicyclic core structures with up to three stereocenters in a single step. The combination of this concept with chiral Bronsted acid bound ortho-quinone methide imines generates a range of interesting fused tetrahydroquinolines in a diastereo- and enantioselective manner.
SYNTHESIS-STUTTGART
(2022)
Review
Chemistry, Organic
Yaseen Hussain, Tamanna, Manisha Sharma, Akshay Kumar, Pankaj Chauhan
Summary: Organocatalysts have shown potential in facilitating remote functionalizations, with the 1,6-addition reaction as a key strategy for creating stereocenters. Furthermore, organocatalysis has enabled the development of complex synthesis through domino reactions.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Biochemistry & Molecular Biology
Jude N. Arokianathar, Will C. Hartley, Calum McLaughlin, Mark D. Greenhalgh, Darren Stead, Sean Ng, Alexandra M. Z. Slawin, Andrew D. Smith
Summary: The isothiourea-catalyzed enantioselective 1,6-conjugate addition of para-nitrophenyl esters to 2,6-disubstituted para-quinone methides is reported, with in situ generation of para-nitrophenoxide from initial N-acylation promoting catalyst turnover. A range of para-nitrophenyl ester products can be isolated or derivatized in situ by addition of benzylamine to give amides at up to 99% yield.
Article
Chemistry, Physical
Fangfang Guo, Jiean Chen, Yong Huang
Summary: Recently, chiral N-heterocyclic carbenes (NHCs) have been established as powerful catalysts for enantioselective bond-forming processes via noncovalent interactions. A bifunctional NHC with an embedded hydrogen-bonding motif has been reported in this study, showing remarkable tolerance of various Michael acceptors in an asymmetric aza-conjugate addition reaction, with catalytic efficiency far exceeding that of the benchmark tertiary amine-thiourea scaffold.
Article
Chemistry, Applied
Feng Jiang, De Zhong, Lan Wang, Leijie Zhou, Lei Wang, Jiaxing Huang, Hongchao Guo
Summary: Under phosphine catalysis facilitated through desilylation, intramolecular annulation/nucleophilic addition of trimethylsilylethynyl benzoxazinanones with electron-deficient imines or alkenes was achieved to afford a series of indole derivatives in moderate to high yields. The use of chiral phosphine achieved asymmetric reaction, leading to a 95% ee of product.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Min Yang, Huiqi Han, Hui Jiang, Shengqing Ye, Xiaona Fan, Jie Wu
Summary: A photoinduced reaction of potassium alkyltrifluoroborates, sulfur dioxide, and para-quinone methides under visible light irradiation at room temperature is developed to give diarylmethyl alkylsulfones in moderate to good yields. The transformation is initiated by alkyl radicals generated in situ from potassium alkyltrifluoroborates, and subsequent steps involve the insertion of sulfur dioxide and radical 1,6-addition of para-quinone methides with alkylsulfonyl radical intermediates.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Organic
Kangkana Chutia, Dhiraj Dutta, Manashi Sarmah, Pranjal Gogoi
Summary: A Pd-catalyzed cascade annulation process involving C-C bond formation and 1,6-conjugate addition for pi-extended benzofulvenes is described. The process is compatible with various functionalities of p-quinone methides and internal alkynes, resulting in diverse pi-extended benzofulvenes. Furthermore, this strategy can also be applied to aryne annulation with p-quinone methides.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Applied
Yishuai Fan, Kaixin Yin, Xiaojie Li, Jinzhe Huang, Ruwei Shen
Summary: This paper describes the development of a tandem conjugate addition-cyclization sequence of p-quinone monoacetals with 2-siloxyphenyl Grignard reagents, resulting in the synthesis of phenol-bridged cyclohexanone derivatives. It also reports a tandem conjugate-addition and dimerization reaction of p-quinone monoacetals with Grignard reagents, leading to the diastereoselective synthesis of complex bridged-ring compounds bearing tricyclo[6.2.2.0(2,7)]dodecene skeletons.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Zhi-Yuan Zhao, Ming Cui, Elisabeth Irran, Martin Oestreich
Summary: This study successfully achieved highly enantioselective silylation of 3-substituted 2H-azirines using a copper-catalyzed reaction with a silyl boronic ester as a latent silicon nucleophile. The resulting C-silylated, unprotected (N-H) aziridines were obtained in high yields and with excellent enantioselectivities, and they can be further converted into valuable compounds without significant loss of enantiomeric excess.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
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)
