Article
Chemistry, Organic
Chao-Jiu Long, Hong-Ping Pu, Yan-Hong He, Zhi Guan
Summary: A novel method for achieving enantioselective alpha-alkylation of secondary acyclic amines with ketones through the combination of photocatalysis and the catalytic promiscuity of lipase is described. Various beta-amino ketones were synthesized from secondary acyclic amines with good yields (up to 89%) and moderate enantio- and diastereoselectivities (up to 89 : 11 er and 93 : 7 dr) under mild conditions without oxidants and cofactors. This method exhibits wide substrate scope, excellent functional group tolerance, and simple operation.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Multidisciplinary Sciences
Marie L. J. Wong, Alistair J. Sterling, James J. Mousseau, Fernanda Duarte, Edward A. Anderson
Summary: Bicyclo[1.1.1]pentanes (BCPs) are essential in contemporary drug design, yet methods to access BCPs with adjacent stereocenters are limited. This study presents a photo- and organocatalyzed asymmetric addition of simple aldehydes to [1.1.1]propellane to generate enantioenriched alpha-chiral BCPs.
NATURE COMMUNICATIONS
(2021)
Review
Chemistry, Multidisciplinary
Philipp Spiess, Saad Shaaban, Daniel Kaiser, Nuno Maulide
Summary: Umpolung is a term describing the reversal of innate polarity, which has become an important tool in synthetic organic chemistry. In this Account, the authors provide an overview of established methods and summarize their findings in the rapidly developing field of umpolung of carbonyl derivatives. They focus on the alpha-umpolung of amides enabled by electrophilic activation and the enolonium chemistry of ketones enabled by hypervalent iodine reagents. The authors discuss the challenges and achievements of these reactions, as well as mechanistic aspects. Rating: 8/10.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Ning Liu, Qi-Fei Liu, Wei Sun, Xiao-Chen Wang
Summary: This study reports the successful direct asymmetric vinylogous Mannich reactions of acyclic alpha, beta-unsaturated ketones using chiral bicyclic bisborane catalysts. The strong Lewis acidity and steric bulk of the bisborane catalysts played crucial roles in achieving high yields and selectivities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Timothy B. Wright, P. Andrew Evans
Summary: The focus has shifted from traditional asymmetric alkylations to catalytic asymmetric enolate alkylation methods, significantly improving the economic and selective aspects of the process. By combining different nucleophiles with carbon-centered electrophiles, various α-stereogenic carbonyl derivatives can be constructed.
Article
Chemistry, Multidisciplinary
Sergio Cuesta-Galisteo, Johannes Schorgenhumer, Xiaofeng Wei, Estibaliz Merino, Cristina Nevado
Summary: This study presents a nickel-catalyzed asymmetric reductive hydroarylation method for synthesizing enantioenriched alpha-arylbenzamides. By using a BIm ligand, diethoxymethylsilane, and aryl halides, aryl groups can be selectively introduced to the internal position of the olefin, creating a new stereogenic center alpha to the N atom with neutral reagents and mild reaction conditions. This provides a straightforward route to pharmacologically relevant motifs found in anticancer drugs, SARS-CoV PLpro inhibitors, and KCNQ channel openers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Eric D. Kalkman, John F. Hartwig
Summary: The study focuses on the Pd-catalyzed asymmetric alpha-arylation of carbonyl compounds, investigating the stereoselectivity and reactivity of arylpalladium enolate intermediates. It reveals that the rate of reductive elimination impacts the enantioselectivity significantly and that complexes with more electron-rich aryl ligands react faster. Noncovalent interactions stabilize the pathway to the major product enantiomer more strongly than to the minor enantiomer.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Cornelius Gartner, Christoph Schneider
Summary: We report a cooperative palladium- and Bronsted acid-catalyzed strategy for the first enantioselective annulation of in situ generated alpha,beta-unsaturated N-acyliminium ions with chiral metal enolates. Novel polycyclic oxoisoindoles with three contiguous stereogenic centers were obtained with good yields, excellent enantiocontrol, and moderate to good diastereoselectivity. The utility of this process was demonstrated by their conversion to synthetically valuable scaffolds.
Article
Chemistry, Organic
Chao-Jiu Long, Hong-Ping Pu, Yan-Hong He, Zhi Guan
Summary: A new method for the direct enantioselective α-alkylation of secondary acyclic amines with simple ketones is described, using a combination of photocatalysis and the catalytic promiscuity of lipase. Various β-amino ketones were synthesized in good yields of up to 89%, with moderate enantio- and diastereoselectivities (up to 89:11 er and 93:7 dr) under mild, oxidant- and cofactor-free conditions. This novel protocol exhibits wide substrate scope, excellent functional group tolerance, and simple operation characteristics.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Bram B. C. Peters, Norman Birke, Luca Massaro, Pher G. Andersson
Summary: The catalytic asymmetric hydrogenation of olefins is a powerful method for synthesizing chiral compounds. By using an iridium N,P-complex catalyst, various prochiral unsaturated amides can be efficiently reduced with high enantioselectivities. The attractive features of this method include its application in the synthesis of fenpropidin and the potential use of isomeric mixtures as starting materials.
Review
Chemistry, Physical
Ummareddy Venkata Subba Reddy, Bheemreddy Anusha, Zubeda Begum, Chigusa Seki, Yuko Okuyama, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: Chiral primary alpha-amino amides, as bifunctional organocatalysts, have been widely used in various asymmetric organic transformations due to their advantageous characteristics, such as low cost, easy synthesis, and the ability to incorporate diverse functional groups.
Review
Chemistry, Physical
Chenlong Zhang, Weipeng Hu, James P. Morken
Summary: In recent years, a-boryl organometallic reagents have become popular as versatile nucleophiles in asymmetric synthesis, enabling chemo- and stereoselective coupling reactions to produce enantioenriched boronic esters. This allows for efficient construction of complex structures with high functional group compatibility. Efforts have been focused on preparing enantiomerically enriched a-boryl organometallic reagents and developing stereoselective reactions of related racemic materials.
Article
Chemistry, Multidisciplinary
Le-Cheng Wang, Bo Chen, Xiao-Feng Wu
Summary: A novel cobalt-catalyzed carbonylative coupling of ethers with amines has been achieved, leading to the synthesis of biologically active compounds. This protocol presents the first example of direct carbonylative reaction of ethers, providing an important method for the construction of alpha-carbonylated ethers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Hirotsugu Suzuki, Sora Kondo, Koichiro Yamada, Takanori Matsuda
Summary: A novel copper-catalyzed diastereo- and enantioselective reductive Mannich-type reaction was developed in this study, providing a direct and scalable synthetic method for enantioenriched beta(2,3,3)-amino acids with vicinal stereogenic centers. The protocol shows excellent synthetic utility and scalability.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Mikel Oiarbide, Claudio Palomo
Summary: Chiral Bronsted base (BB) catalyzed asymmetric transformations are important for synthesis. These transformations involve transiently generated enolate intermediates that react with a variety of electrophiles. Our group focused on developing BB-catalyzed asymmetric reactions of enolizable carbonyl substrates, with an additional challenge of controlling site-selectivity. This account illustrates the opportunities and challenges of these methods, with a focus on generating quaternary carbon stereocenters. New bifunctional BB catalysts and achiral templates were developed during this process.
Article
Chemistry, Organic
Pandur Venkatesan Balaji, Srinivasan Chandrasekaran
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2016)
Article
Chemistry, Organic
Pandur Venkatesan Balaji, Srinivasan Chandrasekaran
Article
Chemistry, Organic
Bo Sun, Roman Pluta, Naoya Kumagai, Masakatsu Shibasaki
Article
Chemistry, Organic
Zhongdong Sun, Bo Sun, Naoya Kumagai, Masakatsu Shibasaki
Article
Chemistry, Multidisciplinary
Pandur Venkatesan Balaji, Lennart Brewitz, Naoya Kumagai, Masakatsu Shibasaki
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Chemistry, Organic
Pandur Venkatesan Balaji, Srinivasan Chandrasekaran
Article
Chemistry, Applied
Lulu Zhang, Jiakai Zhao, Qi Mou, Dawei Teng, Xiangtai Meng, Bo Sun
ADVANCED SYNTHESIS & CATALYSIS
(2020)
Article
Chemistry, Applied
Ruihan Niu, Jiakai Zhao, Qi Mou, Ruyuan Zhao, Jing Zhang, Meiqi Wang, Bo Sun
Summary: An efficient and selective C-H functionalization reaction of indoles into ethynylethylene carbonates has been achieved via (CpCo)-Co-X(III) catalysis, allowing the synthesis of various vinylindoles with high yields and regioselectivity.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Qi Mou, Ruyuan Zhao, Bo Sun
Summary: In the field of synthetic organic chemistry, directing-group-assisted C-H functionalization has been found to be a key tool for the efficient and site-selective construction of C-C and hybrid bonds. Among the C-H functionalization of ferrocene derivatives, the directed group strategy using ferrocene amides is the most commonly used method due to its ease of synthesis and the fine, tuneable, and reversible coordination permitted by its metal center. This review extensively discusses various C-H bond functionalization reactions of ferrocene using amide directing groups.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Multidisciplinary Sciences
Lin-Xin Ruan, Bo Sun, Jia-Ming Liu, Shi-Liang Shi
Summary: Despite the importance of enantioenriched tertiary alcohols bearing two contiguous stereocenters, their efficient synthesis has remained a challenge. In this study, we report a platform for their preparation using nickel-catalyzed addition of organoboronates to racemic ketones, achieving high levels of diastereo- and enantioselectivity.
Article
Chemistry, Organic
Rui-Han Niu, Jing Zhang, Ru-Yuan Zhao, Quan-Jian Luo, Jin-Heng Li, Bo Sun
Summary: A cobalt(III)-catalyzed directed C-7 alkynylation of indolines with easily accessible bromoalkynes has been developed, which provides a powerful route for the synthesis of 7-alkynyl-substituted indolines with broad substrate scope and excellent yields. Furthermore, the reaction can also be applied to the coupling of N-aryl 7-azaindoles, demonstrating the synthetic practicability of this strategy.
Article
Chemistry, Organic
Ru-Yuan Zhao, Jing Zhang, Rui-Han Niu, Jin-Heng Li, Bo Sun
Summary: An efficient synthesis of ferrocene derivatives has been achieved via Ru(ii)-catalyzed direct selective C-H mono-alkynylation using easily accessible bromoalkyne compounds and weakly coordinating amide groups. This method allows for the synthesis of alkynylated ferrocenes with high yields (up to 89%) by utilizing carboxamides for easy alkyne transformation.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Qi Mou, Ruyuan Zhao, Ruihan Niu, Seiya Fukagawa, Taiki Shigeno, Tatsuhiko Yoshino, Shigeki Matsunaga, Bo Sun
Summary: An enantioselective C-H alkylation of ferrocene carboxamides with diazomalonates using an achiral Cp*Ir(iii)/chiral carboxylic acid system is reported, providing planar chiral alkylated ferrocenes in good yields with moderate to good enantioselectivity (up to 94 : 6 er).
ORGANIC CHEMISTRY FRONTIERS
(2021)