Article
Chemistry, Physical
Jae Ho Shim, Ji Yeon Lee, Hyeon Soo Kim, Deok-Chan Ha
Summary: The study developed a catalyst with N-selectivity for the nitroso aldol reaction, using a quantum calculation. The reaction mechanism was determined and optimized, resulting in a high yield of the product with high enantioselectivity. The catalyst provides a less expensive and more environmentally friendly alternative for the reaction.
Article
Chemistry, Multidisciplinary
Che-Sheng Hsu, Carlos R. Goncalves, Veronica Tona, Amandine Pons, Marcel Kaiser, Nuno Maulide
Summary: The article presents a method of synthesizing amine compounds using highly electron-deficient iminium ions and highlights its broad applicability through a specific case study.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Venkati Bethi, Syeda Bakhtawar Zahra, Bapuaro D. Rupanawar, Fujie Tanaka
Summary: This article describes the regioselective aldol reactions of beta-methyl-substituted cyclic enone derivatives with isatins using a catalyst system composed of DBU, pyrrolidine, and DMSO. The reactions resulted in aldol products with bond formation at the methyl group of the beta-methyl-substituted cyclic enone derivatives. This method selectively affords gamma-position-reacted aldol products, expanding the scope of concisely synthesized 3-substituted 3-hydroxyoxindole derivatives.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Ryoga Hikawa, Mio Shimogaki, Taichi Kano
Summary: Novel threonine-derived amino sulfonamide organocatalysts were developed and successfully applied to asymmetric aldol reactions. The reactions produced anti-aldol adducts with high diastereo- and enantioselectivity when catalyzed by threonine-derived tosylamide, and syn-aldol adducts were obtained when using threonine-derived triflamide catalyst in reactions between alpha-siloxyacetone and aromatic aldehydes. In both cases, a significant improvement in diastereoselectivity was observed compared to threonine-derived carboxylic acid catalyst.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Hiroshi Ito, Yuya Yoshida, Tsuguya Masuda, Aiko Sasaki, Kyosuke Imoto, Kohei Sato, Tetsuo Narumi, Nobuyuki Mase
Summary: Fluorescent sensors were used to monitor chemical transformations with increased fluorescence intensity, enabling rapid identification of excellent organocatalytic systems. Through the analysis of data from over 4,000 screenings, a combination of pyrrolidine and isophthalic acid was found to be a catalyst template for the quaternary carbon-containing aldol reaction. After fine-tuning of the catalyst template, 5-hydroxy isophthalic acid was confirmed as a highly reactive additive.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Bin Sun, Pei-Xuan Li, Yu Jiang, Lu-Lu Yang, Pan-Yi Huang, Run-Pu Shen, Mao-Jie Chen, Jia-Yang Wang, Can Jin
Summary: A visible-light-driven desaturative beta-alkoxyoxalyation reaction has been reported. The reaction proceeds under mild conditions and does not require a photocatalyst or transition metal. The C-Br bond undergoes homolysis to produce a difluoroalkyl radical, which then undergoes defluorinated beta-alkoxyoxalylation cascades to yield a wide range of beta-ketoester/ketoamide substituted enamines. The oxygen source for the carbonyl unit is confirmed to be H2O through O-18 labeling experiments.
Article
Chemistry, Multidisciplinary
Jose A. C. Delgado, Fidel E. M. Vicente, Alexander F. de la Torre, Vitor A. Fernandes, Arlene G. Correa, Marcio W. Paixao
Summary: In this study, a library of N-alkylated lipopeptide organocatalysts were synthesized through an isocyanide-based multicomponent reaction. These catalysts were evaluated in the 1,4-addition of aldehydes to trans-beta-nitrostyrene using water as the sole solvent, resulting in excellent yields, diastereoselectivities, and enantioselectivities under sustainable reaction conditions with low catalyst loadings and without additives.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Miku Nomura, Zubeda Begum, Chigusa Seki, Yuko Okuyama, Eunsang Kwon, Koji Uwai, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: The catalytic functionality of new optically active thiourea fused gamma-amino alcohols was investigated in the asymmetric Mannich reaction. Chiral Mannich products, beta-amino keto compounds, with continuous chiral centers were obtained in excellent chemical yield (up to 88%) and stereoselectivities (up to syn : anti/93 : 7 dr, up to 99% ee), making them versatile synthetic intermediates for deriving various biologically active compounds.
Article
Chemistry, Multidisciplinary
Sedigheh Sadat Naeimi, Peyman Salehi, Morteza Bararjanian
Summary: The synthesis of prolinamide derivatives of (R)-tetrahydropapaverine and their application as organocatalysts in asymmetric Aldol reaction were reported. Catalyst 2 showed the best catalytic activity in the reaction between cyclohexanone and 4-nitrobenzaldehyde, achieving up to 90% enantiomeric excess. Unlike the anti-stereoselectivity observed in the presence of L-proline alone, the hybridization with (R)-tetrahydropapaverine resulted in the formation of syn products as the major compounds.
JOURNAL OF THE IRANIAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Qi Zhang, Yao Li, Long Zhang, Sanzhong Luo
Summary: A novel three-component Lewis acid-base catalyst has been developed, utilizing a bulky tertiary amine to activate a Lewis pair for enamine catalysis, allowing for asymmetric control of disulfuration reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Hao Fu, Dan Yang, Di Qiu, Chun Hua Yan, Ren Cai, Yaping Du, Weihong Tan
Summary: A facile colloidal chemistry method is reported to obtain three-dimensional supercuboids from two-dimensional ZnSe nanosheets. The highly stable supercuboids can be readily transformed back to nanosheets through an exfoliation process. The potential application of ZnSe nanosheets in catalysis is demonstrated in the aldol condensation reaction.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Organic
E. H. Nisala Fernando, Jose Cortes Vazquez, Jacqkis Davis, Weiwei Luo, Vladimir N. Nesterov, Hong Wang
Summary: The formation of enamine from primary arylamines was studied and confirmed, with the necessity of a radical quencher for detection. A direct synthesis of alpha-enaminones from primary arylamines and ketones was developed, and a mechanistic investigation suggested the involvement of an amine radical cation. The reactivity and utility of alpha-enaminones were explored, showing different properties from enamines and advancing understanding in organic chemistry.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Sophi R. Todtz, Cory W. Schneider, Tanmay Malakar, Clare Anderson, Heather Koska, Paul M. Zimmerman, James J. Devery
Summary: Lewis acid-catalyzed carbonyl-olefin metathesis has revealed new behaviors of Lewis acids, particularly the solution behaviors of FeCl3. Adding TMSCl to FeCl3-catalyzed carbonyl-olefin metathesis leads to significant deviations from normal reactivity, mitigating byproduct inhibition and increasing the reaction rate. Quantum chemical simulations suggest the formation of a silylium catalyst that binds to carbonyl groups, with potential utility in carbonyl-based transformations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Gen-Fa Wen, Rui Zhang, Chu-Yu Zhang, Chao-Shan Da
Summary: This study compares and explores the catalytic efficiencies of structurally similar alpha- and beta-amino acids in an asymmetric aldol transformation. The results show that both types of amino acids achieve high catalytic efficiencies under different optimal conditions, and in some cases, the beta-amino acid even exhibits higher enantioselectivity than the alpha-amino acid.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Joseph P. Gillions, Salma A. Elsherbeni, Laura Winfrey, Lei Yun, Rebecca L. Melen, Louis C. Morrill, Alexander P. Pulis
Summary: C-H functionalization is an important area in synthetic methodology, and electron-deficient organoboranes have great potential in mediating hydride abstraction from alpha-amino C-H bonds. This review covers recent advances in organoborane-mediated hydride abstraction, focusing on their catalytic applications in alpha- or beta-functionalization, alpha,beta-difunctionalization, and amine dehydrogenation.
