Article
Chemistry, Physical
Yiqi Ren, Maodi Wang, Qihua Yang, Junfa Zhu
Summary: The development of chiral solid catalysts using unconventional strategies is crucial for efficient heterogeneous asymmetric catalysis. The study presents a chiral solid catalyst, chiral diamine modified Ni/SiO2, for asymmetric Michael addition. The experimental results demonstrate that the peripheral Ni sites in close contact with SiO2 support are likely to be the active sites.
Article
Chemistry, Organic
Xin-Xing Wu, Hao Ye, Ming Li, Jianing Qian, Hong Dai, Yujun Shi
Summary: A formal [6 + 1] annulation reaction has been developed through sequential Michael addition/palladium-catalyzed alpha-arylation of ketones, providing an efficient route to diverse acylated caprolactams through double C-C bond formation of the same site from methyl ketones. The reaction features broad substrate scope, good functional group tolerance, easy scale-up, and useful transformations of the products.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Physical
Qihua Yang, Junfa Zhu, Yiqi Ren, Maodi Wang
Summary: In this study, a chiral solid catalyst, chiral diamine modified Ni/SiO2, was prepared for asymmetric Michael addition. The experimental results showed that the chiral diamine modified Ni/SiO2 achieved a higher ee value and turnover frequency compared to chiral Ni complexes. The peripheral Ni sites in close contact with SiO2 support were identified as the active sites, distinct from homogeneous complexes. Continuous flow production of chiral compounds for more than 65 hours was achieved using the solid catalysts in a fixed bed reactor.
Article
Chemistry, Organic
Chandan K. Mahato, Sayan Mukherjee, Mrinalkanti Kundu, Virbhadra P. Vallapure, Animesh Pramanik
Summary: This study utilized a new set of organic catalysts for asymmetric Michael reactions in water, achieving high efficiency and yield, offering a new method for green synthesis. The strategy also successfully synthesized an optically active octahydroindole, a key component found in many natural products.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Yong-Chao Ming, Xue-Jiao Lv, Ying-Han Chen, Yan-Kai Liu
Summary: A highly selective cascade process is demonstrated based on enantioselective iminium-catalyzed conjugate addition of 2-hydroxycinnamaldehydes and 2-oxocarboxylic esters. Normal cinnamaldehydes do not show reactivity under the same reaction conditions. Bridged bicyclic ketals are synthesized, bearing stereocenters on both the bridge carbon and bridgehead ketal carbon.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Haruna Araki, Shohei Furuya, Kazuya Kanemoto, Shin-ichi Fukuzawa
Summary: The conjugated addition reaction of 1-pyrroline-5-carbonitrile to alpha-enones was effectively catalyzed by AgF/ThioClickFerrophos (TCF) in diethyl ether in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and nearly single diastereomers of adducts with good enantiomeric excesses (up to 97% ee) were obtained in high yields. The reduction of the nitrile group with H2/Raney Ni in ethanol successfully transformed the conjugate adduct to the corresponding spirocyclic piperidine (60% yield) as a single stereoisomer.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Takashi Yamazaki, Masahito Taketsugi, Tomoko Kawasaki-Takasuka, Tomohiro Agou, Toshio Kubota
Summary: Using CuBr·SMe2 and TMSCl as catalysts, Michael addition reactions of various Grignard reagents to 4,4,4-trifluorinated alpha, beta-unsaturated carboxylic acid derivatives with 4-substituted oxazolidin-2-ones as a chiral auxiliary proceed smoothly to construct the desired products with quaternary stereocenters possessing a CF3 group in good to excellent yields.
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN
(2021)
Article
Chemistry, Organic
Cheng Huang, Zhifei Zhao, Shiwu Li, Jixing Zhao, Leifang Wu, Chengzhi Gu
Summary: A highly enantioselective conjugate addition has been developed for the reaction between indolizine and its analogues with alpha,beta-unsaturated 2-acyl imidazoles. This method provides excellent yields and enantioselectivities, overcoming the limitations of organocatalysts in controlling stereoselectivity.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Bin Mao, Zhi-Wei Chen, Jian-Fei Wang, Chao-Huan Zhang, Zhi-Qian Du, Chuan-Ming Yu
Summary: In this study, the enantioselective organocatalytic conjugate alkenylation of fi-substituted alkenyl benzimidazoles was achieved, leading to the formation of beta-stereogenic 2-alkyl benzimidazole derivatives with excellent enantio-selectivities. Chiral binaphthols were found to be effective catalysts for promoting the nucleophilic addition of bench-stable alkenyl trifluoroborate salts under mild conditions. By utilizing C=N-containing azaarenes as activating groups, the applications of these catalysts were expanded. The synthetic utility of this strategy was demonstrated by converting the products into several useful enantiomerically enriched benzimidazole building blocks.
Article
Chemistry, Applied
Sloan Ayers, Gregory L. Beutner, Wei Ding, Carolyn Higman, Charles Pathirana, Robert Wethman
Summary: Having reliable methods to monitor catalyst activation processes is crucial for ensuring the reproducibility of catalytic reactions. For asymmetric Diels-Alder reactions, chiral oxazaborolidine or oxazaborolidinium catalysts are powerful reagents that promote these reactions with high yield and selectivity. By investigating the mechanism, several modern analytical methods are compared to quantitate the formation of oxazaborolidine catalyst from amino alcohol and boroxine, leading to useful monitoring methods for this important transformation.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2022)
Article
Engineering, Chemical
Yiying Pang, Bowei Wang, Yazhuo Kang, Jiayi Li, Xiaoyi Gu, Guoqiang Kang, Xilong Yan, Yang Li, Ligong Chen
Summary: In this study, a sulfonated chiral covalent organic framework (SDA-CCOF) was successfully synthesized and used as a catalyst for the asymmetric Michael addition reaction of acetone with nitrostyrene. The catalyst exhibited good catalytic performance with a high enantioselectivity of 90%. It also demonstrated high enantioselectivity for diverse substrates.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Xiao-Yan Dong, Da-Ming Du
Summary: This paper investigated the organocatalytic asymmetric 1,4-Michael addition reaction of azadienes and alpha-thiocyanoindanones, successfully synthesizing a series of chiral thiocyano compounds. By describing a possible reaction mechanism, it broadens the scope of application of azadiene substrates.
Article
Chemistry, Multidisciplinary
En Li, Jiean Chen, Yong Huang
Summary: The Michael reaction is an important method for preparing functional molecules with a β-stereogenic center. However, the enantioselective seleno-Michael addition is still poorly explored. In this study, a highly enantioselective Michael addition reaction of alkyl selenols to enones was reported, introducing a Se atom asymmetrically to an electron-deficient double bond. A chiral bifunctional N-heterocyclic carbene (NHC)/thiourea catalyst was developed and showed remarkable selectivity in delivering chiral β-seleno ketones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Abhisek Midya, Laxman Devidas Khalse, Prasanta Ghorai
Summary: In this study, an amine-catalyzed reductive aldol-condensation followed by an intramolecular reductive Michael-addition cascade was demonstrated, using Hantzsch ester as a hydride source to a keto-bis-enone, leading to the synthesis of enantio- and diastereoselective benzannulated diquinanes with three consecutive stereocenters, including an all-carbon quaternary formyl stereocenter. Interestingly, changing the tether from an aliphatic to an aromatic moiety resulted in a change in reactivity, where an asymmetric aldol reaction, followed by an iminium/enamine isomerization and diastereoselective Michael addition reaction, resulted in the formation of a bis-benzannulated diquinane with vicinal congested quaternary chiral centers.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yong Gao, Zhenda Fu, Di Wu, Hongquan Yin, Fu-Xue Chen
Summary: An efficient bifunctional cinchona alkaloids-catalyzed asymmetric tandem intramolecular oxa-Michael addition/electrophilic thiocyanation method was developed for the synthesis of chiral alpha-thiocyanato flavanones with two vicinal stereocenters. The method produced the desired compounds in good yields with excellent diastereo- and enantioselectivities under mild conditions, demonstrating its potential for scale-up.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemical Research Methods
Silvia Roscales, Torsten Kniess
JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS
(2019)
Article
Chemistry, Multidisciplinary
Silvia Roscales, Aurelio G. Csaky
JOURNAL OF CHEMICAL EDUCATION
(2019)
Article
Chemistry, Multidisciplinary
Silvia Roscales, Aurelio G. Csaky
Article
Chemistry, Applied
Silvia Roscales, Aurelio G. Csaky
ADVANCED SYNTHESIS & CATALYSIS
(2020)
Article
Chemistry, Multidisciplinary
Silvia Roscales, Aurelio G. Csaky
Summary: The method reported in the study utilizes nitrosobenzene as a reagent to activate boronic acid and aldehyde C-H bond simultaneously, triggering the synthesis of ketones through intramolecular migration. This practical and scalable method provides a straightforward approach for ketone synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Maciej Skrodzki, Victor Ortega Garrido, Aurelio G. Csaky, Piotr Pawluc
Summary: This study reports a stable cobalt(II) complex that exhibits high catalytic activity and selectivity in hydrosilylation reactions, with unprecedented tolerance towards tertiary silanes. The catalytic system shows high regioselectivity for a variety of alkynes, resulting in the formation of alpha-vinylsilanes.
JOURNAL OF CATALYSIS
(2022)
Review
Chemistry, Medicinal
Francisco Sanchez-Sancho, Marcos Escolano, Daniel Gavina, Aurelio G. Csaky, Maria Sanchez-Rosello, Santiago Diaz-Oltra, Carlos del Pozo
Summary: The interest in 3,4-dihydropyrimidine-2(1H)-(thio)ones is growing due to their biological relevance. The classical approach to reach these structures is the Biginelli reaction, but it has limitations in product diversity. In this manuscript, two main strategies to overcome these limitations are discussed: modification of the reaction components and postmodification of the products. The modification of the keto ester counterpart is the most popular approach, and the use of Biginelli adducts for further modification is also highlighted.
Meeting Abstract
Radiology, Nuclear Medicine & Medical Imaging
Markus Laube, Silvia Roscales, Jens Pietzsch, Aurelio Csaky
NUCLEAR MEDICINE AND BIOLOGY
(2021)
Review
Chemistry, Multidisciplinary
Silvia Roscales, Aurelio G. Csaky
CHEMICAL SOCIETY REVIEWS
(2020)
Article
Chemistry, Organic
Silvia Roscales, Nicole Bechmann, Jens Pietzsch, Torsten Kniess