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, 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, Organic
Al -Hassan S. Mahdy, Salem E. Zayed, Ahmed M. Abo-Bakr, Entesar A. Hassan
Summary: This review focuses on referenced research findings about the chemistry of camphor and its applications in the literature. It covers the various methods for synthesizing camphor and its reactions, and outlines the most significant advancements in complexation and organocatalysis based on the camphor skeleton.
Article
Energy & Fuels
Yun Wang, Xin-Yi Liang, Xin-Yi Chen, Zhi-Hui Liang, Hong Cheng, Xiang Li, Li-Ling Li
Summary: This study demonstrates that bovine pancreatic lipase can catalyze the reaction between aromatic aldehydes and cyclic ketones in water, leading to high yields and good stereoselectivity of the aldol products.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Biochemistry & Molecular Biology
Dominika Iwan, Karolina Kaminska, Elzbieta Wojaczynska
Summary: Chiral 2-azabicycloalkane-based catalysts were designed, synthesized and tested, showing excellent catalytic activity and selectivity in aldol reactions. By optimizing the catalyst structure, aldol products were successfully synthesized with high yields up to 95%.
Article
Chemistry, Multidisciplinary
Jingdong Wang, Yuxin Liu, Zhonglin Wei, Jungang Cao, Dapeng Liang, Yingjie Lin, Hai-feng Duan
Summary: A series of chiral thiourea compounds with multiple H-bond donors derived from hydroquinine have been reported. The aza-Henry reaction of isatin-derived ketimines and long-chain nitro-alkanes catalyzed by these chiral thioureas shows high enantioselectivity and excellent diastereoselectivity. This work represents the first report on long-chain nitroalkanes as substrates with excellent diastereoselectivity in metal-free catalytic systems.
Article
Chemistry, Organic
He Liu, Wenjiao Yang, Shaojiu Zheng, Yang He, Guan Wang, Hongjian Qin, Fuqiang Zhu, Xiangrui Jiang, Jingshan Shen, Xudong Gong
Summary: In this study, a convenient and novel route for the synthesis of 3,5-Di-O-benzoyl-2-deoxy-2-chloro-2-C-methyl-D-ribono-c-lactone 5a and its analogues was developed using an Evans-Aldol reaction in the presence of TiCl4. The target compound 5a was efficiently produced on a kilogram scale with a high yield and purity, and 3,5-Di-O-benzoyl-2-deoxy-2-fluoro-2-C-methyl-D-ribono-c-lactone 5b was also successfully synthesized.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Physical
Chonglong Li, Jihai Wang, Huiyun Ding
Summary: The novel helical poly(phenyl isocyanide) showed high optical activity in asymmetric aldol reaction and exhibited enhanced stereoselectivity compared to small molecule l-proline. The helical polymer catalysts can be easily recovered and reused for at least five cycles with maintained activity and stereoselectivity.
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, Applied
Xiao-Pan Chen, Jin-Xin Liu, Hong-Yan Li, You-Cai Xiao, Fen-Er Chen
Summary: A tertiary amino-thiourea catalyzed asymmetric aldol reaction between 2-isocyanatomalonate esters and isatins has been achieved, leading to the formation of optically active spirooxazolidinone oxindole derivatives with excellent yields and enantioselectivities under mild conditions. This work provides an updated example of using isatins as electrophiles in the asymmetric aldol reaction with 2-isocyanatomalonate esters.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
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
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, Organic
Simone Gallarati, Ruben Laplaza, Clemence Corminboeuf
Summary: In this study, a fragment-based approach is introduced to evaluate the combinations of building blocks and extract mechanistic insight in the design of bifunctional hydrogen-bond donors/amines as organocatalysts. The use of volcano plots and activity maps allows for faster and more transferable activity-based screening.
ORGANIC CHEMISTRY FRONTIERS
(2022)
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
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)