Review
Chemistry, Multidisciplinary
Diksha Gambhir, Sanjay Singh, Ravi P. Singh
Summary: The rational combination of two catalysts has been widely used in the synthesis of biologically and pharmacologically relevant chiral compounds. This review article focuses on the achievements in asymmetric catalysis and synthesis using enamine and iminium-based dual organocatalytic systems. The combination of enamine/iminium catalysis with other organocatalytic systems has paved the way for the construction of complex chiral compounds.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Review
Chemistry, Applied
Daniel Gavina, Marcos Escolano, Javier Torres, Gloria Alzuet-Pina, Maria Sanchez-Rosello, Carlos del Pozo
Summary: Substituted and annulated pyrroles containing chiral centers can be accessed through organocatalytic enantioselective Friedel-Crafts alkylation (FCA) reaction. These compounds are interesting due to their natural occurrence and diverse biological activities. In the past two decades, significant synthetic efforts have been made to develop asymmetric transformations involving pyrroles in the FCA reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Ryo Tsuyusaki, Kosuke Nakashima, Yasuyuki Matsushima, Shin-ichi Hirashima, Tsuyoshi Miura
Summary: This study demonstrates the successful application of a thiourea organocatalyst in the direct construction of vicinal all-carbon quaternary stereocenters bearing a trifluoromethyl group. The reaction yields high amounts of spirooxindole derivatives with excellent enantioselectivities reaching up to 99% ee.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Tino P. Golub, Taichi Kano, Keiji Maruoka, Christian Merten
Summary: We present a VCD spectroscopic characterization of a chiral catalyst and show that the VCD spectra of in situ generated enamine and ex situ prepared iminium ion are different. This study highlights the potential of VCD spectroscopy in distinguishing stable intermediates and determining the dominant conformers in solution.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Yue Liu, Ying Zhang, Qian-Wei Huang, Chuan Gou, Qing-Zhu Li, Qing-Song Dai, Hai-Jun Leng, Jun-Long Li
Summary: Asymmetric construction of pharmacologically interesting tetrahydrofuranyl spirooxindole frameworks has been successfully achieved through organocatalytic reactions, with remarkable results in terms of yield and stereochemistry. The synthetic derivatives show significant anticancer activity against a panel of cancer cell lines, demonstrating their potential as therapeutic agents.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Zhanyong Tang, Ke Mo, Xiaoqiang Ma, Jialin Huang, Depeng Zhao
Summary: The direct C-H trifluoromethylation of arenes via a radical pathway has recently gained considerable attention. However, a major challenge in C-H trifluoromethylation is the lack of site-selectivity on the phenyl ring, especially para-selectivity. Here, we demonstrate a new strategy for para-selective C-H trifluoromethylation of benzamide derivatives using iminium activation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
E. L. Vargas, N. Esteban, J. Cencerrero, V Frances, C. Alvarez, J. A. Miguel, A. Gallardo, A. E. Lozano, M. B. Cid
Summary: A new set of catalytic materials with a pyrrolidine moiety confined in microporous organic polymer networks (POPs) has been developed. These polymers efficiently catalyze the formation of nitrones under mild and sustainable conditions using green solvents through an iminium ion activation mechanism. The polymers are scalable and easily recyclable.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Chemistry, Organic
Venkati Bethi, Fujie Tanaka
Summary: Catalytic asymmetric Mannich reactions of beta-ketocarbonyl derivatives, such as beta-ketoesters and (2-oxopropyl)-phosphonate, have been reported. These reactions result in the formation of C-C bonds at the gamma-position of the beta-ketocarbonyl derivatives with high enantioselectivities. The reversible bond formation at the alpha-position of the beta-ketoester and the stable formation of the gamma-position-reacted product delta-amino beta-ketoester derivative are attributed to the dynamic kinetic process under catalytic conditions.
Article
Chemistry, Organic
Rui Ma, Jia-Lu Zhang, Xiu-Qin Hu, Peng-Fei Xu
Summary: A series of optically active 3,3'-pyrrolidinyl-dispirooxindole derivatives containing a CF3 moiety have been efficiently synthesized through asymmetric catalytic cascade reactions catalyzed by cinchona derived bifunctional squaramide catalyst, resulting in the formation of four contiguous stereogenic centers, two of which are vicinal spiro-stereocenters. Additionally, a wide range of substituted products were obtained with moderate to high yields (up to 99% yield) and excellent stereoselectivities (up to > 20:1 dr for all cases and up to 99% ee).
SYNTHESIS-STUTTGART
(2023)
Review
Chemistry, Organic
Yongchao Wang, Angel A. Cobo, Annaliese K. Franz
Summary: This review summarizes recent advances in the enantioselective construction of spirooxindoles using chiral phosphoric acids, amines, and bifunctional thiourea/squaramides as catalysts.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Applied
Amit Shikari, Koushik Mandal, Deepak Chopra, Subhas Chandra Pan
Summary: A new organocatalytic asymmetric synthesis method has been developed for the synthesis of cyclic acetals with a spirooxindole skeleton. It was found that a bifunctional squaramide catalyst with an adamantyl motif was the most effective in the cascade reaction, providing high diastereo- and enantioselectivities for the desired products.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Qi-Ying Zhang, Lu-Xin Li, Song-Lin Wang, Jing Ma, Hai-Ming Guo
Summary: An electrochemically-driven organocatalytic enantioselective oxidative coupling of tetrahydroisoquinolines and acrylaldehyde was developed, leading to various chiral C1-alkenyl tetrahydroisoquinolines derivatives with yields of 69-86% and er of 93:7-96:4. This synthetic route offers access to various optically active C1-substituted tetrahydroisoquinolines derivatives.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Review
Chemistry, Organic
Man-Su Tu, Ke-Wei Chen, Ping Wu, Yu-Chen Zhang, Xiao-Qin Liu, Feng Shi
Summary: Chemists have successfully synthesized a variety of chiral indole derivatives with optical purity and structural complexity through the design and development of indole-containing platform molecules and their related catalytic asymmetric reactions. Vinylindoles have been proven to be an effective platform molecule for accessing enantioenriched indole derivatives via catalytic asymmetric reactions.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Applied
Yuchen Jie, Huiqin Hu, Ze-Feng Xu, Shengguo Duan, Chuan-Ying Li
Summary: 3-Methylidene-2,3-dihydropyrroles with an ester or keto group at the C4 position were synthesized in moderate to good yields from enamine-tethered triazoles in the presence of a rhodium(II) catalyst. A proposed mechanism involves a formal 1,2-enamine migration/cyclization cascade triggered by the formation of an alpha-amino carbene. The unique reactivity of the exocyclic double bond makes this synthesis useful for the introduction of functional groups. The resulting dihydropyrrole is stable under neutral, weakly acidic, or weakly basic conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Suhas Balasaheb Mitkari, Alberto Medina-Ortiz, Jose Luis Olivares-Romero, Miguel A. Vazquez, Eduardo Pena-Cabrera, Clarisa Villegas Gomez, David Cruz Cruz
Summary: The study introduces an aminocatalytic privileged diversity-oriented synthesis (ApDOS) strategy for constructing diverse and complex thiopyrans-piperidone fused rings, as well as facilitating a super cascade reaction to assemble nine fused rings. Furthermore, by linking an indole moiety on the dithioamide, a Pictet-Spengler type reaction can be promoted, leading to the synthesis of more complex fused ring derivatives in a one-pot process. This investigation opens up new perspectives for the synthesis of a new class of complex and diverse thiopyrans, expanding the chemical space.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
