Article
Chemistry, Applied
Yujiro Hayashi, Masashi Tomikawa, Naoki Mori
Summary: The asymmetric cross-aldol reaction is a synthetically relevant reaction. The reactivity and stereoselectivity of different catalysts were compared for the reaction, and it was found that the proper selection of catalysts can lead to the synthesis of chiral building blocks with high diastereoselectivities and enantioselectivities.
ADVANCED SYNTHESIS & CATALYSIS
(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
Yujiro Hayashi
Summary: The aldol reaction is a significant carbon-carbon bond-forming reaction in organic chemistry. The use of trifluoromethyl-substituted diarylprolinol as an organocatalyst has been found to be effective in promoting cross-aldol reactions with excellent selectivities.
Article
Chemistry, Multidisciplinary
Stuart C. D. Kennington, Saul F. Teloxa, Miguel Mellado-Hidalgo, Oriol Galeote, Sabrina Puddu, Marina Bellido, Pedro Romea, Felix Urpi, Gabriel Aullon, Merce Font-Bardia
Summary: A direct and asymmetric aldol reaction of N-acyl thiazinanethiones with aromatic aldehydes catalyzed by chiral nickel(II) complexes was reported. The reaction gives high yields of O-TIPS-protected anti-aldol adducts with remarkable stereocontrol and atom economy. The removal of the achiral scaffold provides enantiomerically pure intermediates with synthetic interest for producing anti-alpha-amino-beta-hydroxy and alpha,beta-dihydroxy carboxylic derivatives, with theoretical calculations explaining the observed high stereocontrol.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Yu-Xia Liu, Zhi-Wei Ma, Chuan-Chuan Wang, Qian Li, Wen-Peng Mai
Summary: This study demonstrates the application of isosteviol-derived bifunctional primary amine-squaramide organocatalysts in the Michael addition reaction between nitroalkenes and acetophenone, yielding high yields and good enantioselectivity at room temperature.
LETTERS IN ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Santanu Mondal, Ravindra D. Aher, Venkati Bethi, Yu-Ju Lin, Tohru Taniguchi, Kenji Monde, Fujie Tanaka
Summary: This study reports amine-based catalyst systems for the enantioselective Mannich reactions of pyruvates as nucleophiles. The reactions of pyruvates and cyclic sulfonylimines yielded the desired Mannich products, including those with tetrasubstituted carbon centers, in high yields and enantioselectivities. The choice of acid in the amine-based catalyst system played a key role in the formation of Mannich products with high enantioselectivities.
Article
Chemistry, Physical
Kemiao Hong, Jirong Shu, Shanliang Dong, Zhijing Zhang, Yicheng He, Mengting Liu, Jingjing Huang, Wenhao Hu, Xinfang Xu
Summary: An achiral dirhodium complex and chiral phosphoric acid cooperatively catalyze the asymmetric three-component reaction of enynal with alcohol and imine, resulting in the formation of chiral alpha-furyl-beta-amino carboxylates with good to high yields and excellent stereoselectivity. This method efficiently prepares complex furan derivatives with adjacent quaternary and tertiary stereocenters.
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
Teng Yuan, Kelton Radefeld, Chuan Shan, Carter Wegner, Erin Nichols, Xiaohan Ye, Qi Tang, Lukasz Wojtas, Xiaodong Shi
Summary: Here, we have reported an intermolecular asymmetric hydrative aldol reaction by using a vinyl-gold intermediate under ambient conditions. This reaction provides a base-free approach to β-hydroxy amides with high efficiency, yielding up to 95% and with over 50 examples. The use of vinyl gold intermediate as a reactive nucleophile and Fe(acac)(3) as a critical co-catalyst prevents undesired protodeauration, allowing the transformation to proceed under mild conditions with excellent functional group tolerance and stereoselectivity (>20:1 d.r. and up to 99% ee).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Environmental
Celine Demeese, Clara Lods, David-Alexandre Buisson, Edmond Gravel, Irishi N. N. Namboothiri, Eric Doris
Summary: A proline analog assembled on carbon nanotubes was utilized as a heterogenized catalyst in asymmetric aldol reactions, showing high efficiency, good enantioselectivity, and sustainability using pure water as the solvent. The catalyst operates with low loadings and can be recycled without loss of performance, resulting in aldol products with yields up to 99% and enantiomeric excesses up to 98%.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Miguel Sanchez-Fuente, Alberto Lopez-Magano, Alicia Moya, Ruben Mas-Balleste
Summary: Condensation of BINAPO-(PhCHO)(2) and 1,3,5-tris(4-aminophenyl)benzene(TAPB) leads to a new imine-based chiral organic material (COM) that can be post-functionalized through reductive transformation of imine linkers to amines. Although the imine-based material is not stable enough to be used as a heterogeneous catalyst, the reduced amine-linked framework can be efficiently utilized in asymmetric allylation of various aromatic aldehydes. The obtained yields and enantiomeric excesses are comparable to those observed for the molecular BINAP oxide catalyst, with the added advantage of recyclability offered by the amine-based material.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Organic
Isaac G. Sonsona, Andrea Vicenzi, Marco Guidotti, Giorgiana Denisa Bisag, Mariafrancesca Fochi, Raquel P. Herrera, Luca Bernardi
Summary: The study demonstrates the improved selectivity of an asymmetric aldol reaction by replacing part of the catalyst, and identifies the most suitable reaction conditions. However, these conditions seem to be limited to oxindoles bearing a 3-substituent of funapide.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Yuki Uwaso, Naoki Yokoyama, Taichi Kano
Summary: Novel axially chiral biphenyl-based amine catalysts were synthesized from dibromopyrenes, and these chiral amines proved to be effective catalysts for asymmetric reactions through enamine intermediates.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
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
Biochemistry & Molecular Biology
Alejandro Torregrosa-Chinillach, Rafael Chinchilla
Summary: This study demonstrates the enantioselective synthesis of succinimides by the conjugated addition of ketones to maleimides, catalyzed by a simple primary amine-salicylamide. The reaction gives the desired compounds in good to excellent yields and with moderate to excellent enantioselectivities.
