Article
Chemistry, Organic
Esra Dundar, Cihangir Tanyeli
Summary: A series of chiral bifunctional squaramide organocatalysts were evaluated for their application in Friedel-Crafts alkylation of indoles, showing high enantioselectivity and moderate yields. This new asymmetric transformation provides a simple, efficient, clean, and environmentally friendly route for chemical synthesis.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Organic
Zeynep Dilsad Susam, Bilge Deniz Ozcan, Enis Kurtkaya, Erol Yildirim, Cihangir Tanyeli
Summary: In this study, bifunctional quinine-derived organocatalysts were used to catalyze the asymmetric Friedel-Crafts/S(N)2 domino reaction, resulting in enantiomerically enriched products. Density functional theory calculations were also performed to explain the stereoselectivity of the products.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Kosuke Nakashima, Sumire Hanamura, Aoi Imamura, Yasuyuki Matsushima, Shin-ichi Hirashima, Tsuyoshi Miura
Summary: This study investigates the asymmetric Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated trifluoromethyl ketones using a squaramide organocatalyst. The squaramide organocatalyst efficiently promotes the reaction, yielding products with both indole motif and trifluoromethyl group in high yields and excellent enantioselectivities (up to 99% ee). The transformation of the obtained adduct to a chiral spiro indoline 3-one is also demonstrated.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Shui-Li Liu, Qi-Wei Chen, Zhen-Wei Zhang, Qing Chen, Lian-Qiang Wei, Ning Lin
Summary: In this study, two stable Fe(II) coordination compounds were synthesized and showed different catalytic activities when used for the Friedel-Crafts reaction. Compound 2 exhibited superior catalytic activity compared to 1 due to the coordination sites in Fe(II) facilitating intermediate formation and enhancing the electrophilic nature of beta-nitroalkenes. The high functional group and solvent tolerance of catalyst 2 allows for at least 3 times of recycling and reuse without significant loss of catalytic activity. This work presents a new strategy for the synthesis of indole alkaloids under ambient conditions.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Chemistry, Organic
Takanori Shibata, Mio Sasaki, Masafumi Kojima, Mamoru Ito
Summary: The chiral Ir(I)-catalyzed intermolecular reaction of N-carbamoylpyrrole and indole derivatives with alpha,beta-unsaturated carbonyl compounds proceeded with high enantioselectivity, yielding chirally functionalized pyrroles and indoles as formal C-H conjugate adducts. The reaction mechanism was further investigated through deuterium labeling experiments.
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
Yuki Saito, Shu Kobayashi
Summary: The article discusses the application of chiral heterogeneous Sc catalysts in continuous-flow reactions, achieving efficient synthesis of compounds through noncovalent interactions and the crucial role of heteropoly acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Ran Chen, Qian-Qian Yan, Shao-Jun Hu, Xiao-Qing Guo, Li-Xuan Cai, Dan-Ni Yan, Li-Peng Zhou, Qing-Fu Sun
Summary: By varying the metal/ligand ratio, dinuclear triple helicates or mononuclear pincer complexes can be selectively obtained from the same chiral bis-tridentate ligand, with both complexes demonstrating catalytic properties in asymmetric Friedel-Crafts alkylation reactions due to the presence of open metal sites.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Velu Saravanan, Arasambattu K. Mohanakrishnan
Summary: A one-pot synthesis of aryl- and heteroaryl-annulated carbazoles was achieved from 2/3-bromomethylindoles, along with a bis-domino reaction of 2,5-bis(bromomethyl)pyrrole with selected heteroarenes. The synthesized thienocarbazoles and thienodibenzofurans were successfully utilized for a second-generation domino reaction.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Minghe Sun, Min Liu, Changkun Li
Summary: The chemodivergent regio- and enantioselective allylic alkylation of indoles catalyzed by Rh/bisoxazolinephosphane enables the selective formation of chiral C3- and N1-allylindoles with high branched/linear ratio and up to 99% ee by adjusting the counteranion of Rh, the allylic carbonate, reaction temperature, and the ligand.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Biochemistry & Molecular Biology
Mohammad Shahidul Islam, Abdullah Saleh Alammari, Assem Barakat, Saeed Alshahrani, Matti Haukka, Abdullah Mohammed Al-Majid
Summary: Five new C-2-symmetric chiral ligands were synthesized from enantiopure amino alcohols, and used for Friedel-Crafts asymmetric alkylation. The bis(oxazolinyl)thiophene ligands showed higher efficiency in inducing asymmetric alkylation compared to bis(imidazolinyl)thiophene analogues.
Article
Chemistry, Multidisciplinary
Ning Li, Wenjing Lu, Weizhi Gu, Kuiliang Li, Jindong Li, Yangmian Lu, Zhenggen Zha, Zhiyong Wang
Summary: An asymmetric Michael/hemiketalization reaction was developed between isatin-derived beta, gamma-unsaturated alpha-ketoesters and 4-hydroxycoumarins in aqueous media. A series of chiral spirooxindole derivatives with an all-carbon quaternary stereogenic center were obtained in high yields (up to 93%) and excellent enantioselectivities (up to 98%).
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jin Jiaping, Alemayehu Gashaw Woldegiorgis, Xufeng Lin
Summary: Here, we report an enantioselective protocol for the chiral phosphoric acid-catalyzed addition of 3-arylisoxazol-5-amines to highly reactive 3-methide-3H-pyrroles. This protocol provides a diverse range of heterotriarylmethanes bearing an amino acid moiety in good yields (up to 97%) and high enantioselectivities (up to 93% ee) under mild conditions. The utilization of a chiral spirocyclic phosphoric acid is crucial in converting the initial 1H-pyrrol-3-yl carbinols into reactive 3-methide-3H-pyrroles and achieving the desired enantioselective transformation.
Article
Chemistry, Multidisciplinary
Yao Yang, Yurong Sun, Wenliang Gao, Tao Yang
Summary: The dual-site synergistic effect in heterogeneous catalysis is intriguing but complex. It involves two spatially separated and functionally independent active sites for the adsorption and activation of at least two substrate molecules. This complexity becomes more challenging when the substrate molecules are large. In this study, the replacement of Al3+ with Co2+ in Al4B6O15 lattice creates unsaturated Co2+ (4-fold coordination) and oxygen vacancies (O-v). These dual sites, acting as Lewis acid and oxygen adsorption sites, synergistically catalyze the Friedel-Crafts alkylation reactions of nitro-substituted molecules and indole derivatives. The catalyst exhibits high durability and the addition of hydrogen further enhances its catalytic activity, providing a novel perspective on the development of dual-site catalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Review
Chemistry, Physical
Reuben B. Leveson-Gower, Gerard Roelfes
Summary: Friedel-Crafts alkylation and acylation reactions are important in synthetic and industrial chemistry. Researchers have expanded the application of these reactions through directed evolution and created bio-hybrid catalysts. This review summarizes these efforts and discusses future routes for more efficient and benign Friedel-Crafts reactions.
