Article
Chemistry, Multidisciplinary
Jiabin Ni, Xiaowen Xia, Wei-Feng Zheng, Zhaobin Wang
Summary: Cyclopropanols and cyclopropylamines are important structural motifs in medicinal chemistry and exhibit diverse reactivities in organic synthesis. However, the development of a general protocol for obtaining these cyclopropyl derivatives from stable and readily available starting materials remains a challenging task due to the high ring strain energy. In this study, a Ti-based catalyst was found to effectively promote the diastereoselective syntheses of cyclopropanols and cyclopropylamines from widely accessible carboxylic derivatives and terminal olefins. This method represents the first example of directly converting alkyl carboxylic acids into cyclopropanols and offers broad substrate scope and good functional group compatibility.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Katsuki Endo, Daiki Tomon, Satoru Arimitsu
Summary: This paper reports the highly enantioselective alpha-fluorination of both cyclic and acyclic beta-dicarbonyl compounds, achieving yields of 50-99% with excellent enantioselectivity (up to 98% ee). By using beta,beta-diaryl serines as primary amine organocatalysts and adding alkali carbonates (such as Na2CO3 or Li2CO3), the reaction could be conducted with only 1.1 equiv of Selectfluor.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Lei Zhao, Xiao Meng, Yifeng Zou, Junsong Zhao, Lili Wang, Lanlan Zhang, Chao Wang
Summary: This report describes an intermolecular syn-arylalkylation and alkenylalkylation of alkenyl amines with two different organohalides using a Ni(II) catalyst. By utilizing cleavable bidentate quinolinamide, the reaction enables olefin difunctionalization with high levels of regio-, chemo-, and diastereocontrol, providing rapid access to branched aliphatic amines with high diastereoselectivities.
Article
Chemistry, Organic
Zi-Qi Hu, Xiang Li, Li-Xia Liu, Chang-Bin Yu, Yong-Gui Zhou
Summary: A concise and effective ruthenium-catalyzed asymmetric transfer hydrogenation was developed for the synthesis of cis-beta-substituted alpha-hydroxybutyrolactone derivatives with excellent yields and selectivities. This one-step reaction can construct two consecutive stereogenic centers and be scaled up without loss of activity. Additionally, the reductive products can be easily converted into useful building blocks.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jorge Victoria-Miguel, William H. Garcia-Santos, Alejandro Cordero-Vargas
Summary: An efficient visible light catalyzed method for the preparation of 2,3-dihydrofurans using 2-bromoketoesters as radical precursors and alkyl enol ethers as acceptors was reported. The photoredox cycle provides an oxonium ion that is captured by an internal nucleophile to yield the corresponding dihydrofurans. The obtained products contain a versatile acetal moiety at C-2, allowing for the transformation into various heteroaromatic and nonaromatic compounds.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Fei Ling, Yifan Wang, An Huang, Ze Wang, Shiliang Wang, Jiayin He, Xianghua Zhao, Weihui Zhong
Summary: An iridium/f-diaphos catalytic system for the enantioselective hydrogenation of alpha-substituted beta-ketoesters via dynamic kinetic resolution was reported. The desired anti beta'-hydroxy-beta-amino esters were obtained in moderate to good yields with high enantioselectivity and diastereoselectivity. This protocol is tolerant to various functional groups and can be easily conducted on gram scale with lower catalyst loading.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Xiaosa Lu, Jie Zhu, Yinhua Huang
Summary: A rhodium-catalyzed highly enantio- and diaster-eoselective alkenylation reaction of Ay-unsaturated butenolides is reported. The use of a chiral diene ligand enables the synthesis of chiral butyrolactones in high yields with extremely high enantioselectivities and high diastereoselectivities. The key process involves the isomerization of butenolides and subsequent dynamic kinetic resolution.
Article
Chemistry, Multidisciplinary
Arnab Dey, Anurag Singh, Chandra M. R. Volla
Summary: The efficient oxidative [3 + 2] annulation reaction of aryl hydrazones and heterobicyclic alkenes has been achieved using inexpensive cobalt salts under aerobic conditions. The reaction generates complex indane derivatives with high anti-diastereoselectivity, avoiding the use of stoichiometric amounts of metal oxidants.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Shaoren Yuan, Eric J. McLaren, Stefan France
Summary: A general approach to intermolecular benzylic C(sp(3)) H alkylation of methyl-substituted arenes using metal carbenes derived from N-aryl-alpha-diazo-beta-amidoesters and dirhodium catalysts is reported. The alkylated products were formed in up to 81% yield with demonstrated functional group tolerance, surpassing previous literature. The unique amide-ester scaffolding can be exploited through various derivatizations, offering broad synthetic utility and serving as a starting point for the development of selectivity rules and reactivity profiles for these intermolecular C(sp(3)) H functionalizations.
Article
Chemistry, Multidisciplinary
Shiyao Liu, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: In this study, propargylic substitution reactions using ruthenium and copper catalysis with N-monosubstituted hydrazones as ambident nucleophiles were investigated. It was found that N-monosubstituted hydrazones exhibited different reactivities depending on the catalytic system, resulting in either propargylic alkylated or aminated products. DFT calculations were used to study the reaction pathways and further transformation of the products yielded multisubstituted pyrazoles in good to high yields.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Editorial Material
Chemistry, Multidisciplinary
Shiyao Liu, Yoshiaki Tanabe, Shogo Kuriyama, Ken Sakata, Yoshiaki Nishibayashi
Summary: The cover of this issue features the research on the propargylic substitution reaction of propargylic alcohol with an N-monosubstituted hydrazone, where the nucleophilicity of the hydrazone is controlled by the choice of catalytic system. The full article can be accessed at 10.1002/chem.202103287.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Emily R. Sherman, William R. Cassels, Jeffrey S. Johnson
Summary: Asymmetric Michael additions are powerful tools for synthesizing stereochemically complex products. In this Letter, crystalline ss-keto esters were used to achieve a two-phase, one-pot merger of an asymmetric Michael addition with a crystallization-induced diastereomer transformation.
Article
Chemistry, Multidisciplinary
Enrique Reyes-Bravo, Dino Gnecco, Jorge R. Juarez, Maria L. Orea, Sylvain Bernes, David M. Aparicio, Joel L. Teran
Summary: This study describes the synthesis of new chiral highly functionalized zwitterionic bicyclic lactams starting from acyclic beta-enaminoesters derived from (R)-(-)-2-phenylglycinol. The key step involves an intramolecular non-classical Corey-Chaykovsky ring-closing reaction of the corresponding sulfonium salts derived from beta-enaminoesters. This methodology allows for the generation of two or three new stereogenic centers with high diastereoselectivity, and the utility of these intermediates was demonstrated by the stereocontrolled total synthesis of cis-4-hydroxy-2-methyl piperidine and its corresponding pipecolic acid derivative.
Article
Chemistry, Organic
Peng Guo, Guo-Cai Yuan, Liu-Hui Xu, Ke-Yin Ye
Summary: A cobalt-catalyzed modular [3 + 2] assembly of unsaturated hydrocarbons and beta-dicarbonyls is reported. This method showcases mild reaction conditions and a wide range of substrates, enabling the synthesis of diverse multi-functionalized dihydrofuran and furan derivatives.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Physical
Luis Tarifa, M. Pilar del Rio, Laura Asensio, Jose A. Lopez, Miguel A. Ciriano, Ana M. Geer, Cristina Tejel
Summary: A straightforward catalytic method for the synthesis of complex C-substituted piperazines has been developed based on an uncommon head-to-head coupling of easily prepared imines. This efficient process allows the selective formation of a sole diastereoisomer, exhibits a broad substrate scope, and shows good functional group tolerance using a bench-stable iridium catalyst under mild reaction conditions. The addition of N-oxides notably enhances the catalytic activity and selectivity.
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
