35059-50-8Relevant academic research and scientific papers
Dramatic influence of ester steric hindrance on the diastereoselectivity of a Michael addition towards the synthesis of the ABC tricycle of hexacyclinic acid
Audic, Alexandre,Oriez, Rapha?l,Prunet, Jo?lle
, (2021)
During our studies toward the synthesis of the ABC ring system of hexacyclinic acid, we observed an unexpected influence of the steric bulk of the ester group of the Michael acceptor in a key conjugate addition. We propose an eight-membered ring transition state to explain the formation of the undesired diastereomer in the case of unhindered esters.
Homologation of Electron-Rich Benzyl Bromide Derivatives via Diazo C-C Bond Insertion
Modak, Atanu,Alegre-Requena, Juan V.,De Lescure, Louis,Rynders, Kathryn J.,Paton, Robert S.,Race, Nicholas J.
supporting information, p. 86 - 92 (2021/12/27)
The ability to manipulate C-C bonds for selective chemical transformations is challenging and represents a growing area of research. Here, we report a formal insertion of diazo compounds into the "unactivated"C-C bond of benzyl bromide derivatives catalyzed by a simple Lewis acid. The homologation reaction proceeds via the intermediacy of a phenonium ion, and the products contain benzylic quaternary centers and an alkyl bromide amenable to further derivatization. Computational analysis provides critical insight into the reaction mechanism, in particular the key selectivity-determining step.
Catalytic Ring Expansion of Activated Heteroarenes Enabled by Regioselective Dearomatization
Kim, Jiyoung,Yoo, Eun Jeong
supporting information, p. 4256 - 4260 (2021/06/28)
Catalytic ring expansion of activated heteroarenes through 1,4-dearomative addition of diazoacetates was established for the construction of various fused azepines by an elaborate control of the reaction kinetics at each step. The use of a silver catalyst was essential to drive the overall reaction for generating the desired seven-membered azepines. Because of the excellent substrate scope and selectivity, the developed methodology presents an innovative approach for the synthesis of multifused azepines, which are biologically relevant molecules.
Erratum: Oxazaborolidinium Ion-Catalyzed Cyclopropanation of α-Substituted Acroleins: Enantioselective Synthesis of Cyclopropanes Bearing Two Chiral Quaternary Centers (J. Am. Chem. Soc. (2011) 133:51 (20708?20711) DOI: 10.1021/ja209270e)
Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
supporting information, p. 6021 - 6022 (2021/05/13)
Pages 20709 and 20710. In the published version of the paper, the trans:cis ratios of 2w and 2x were reversed. The revised results were confirmed by NOE experiments and comparison of the optical rotation data with reported values after transformation. The
Tridentate Nickel(II)-Catalyzed Chemodivergent C-H Functionalization and Cyclopropanation: Regioselective and Diastereoselective Access to Substituted Aromatic Heterocycles
Nag, Ekta,Gorantla, Sai Manoj N. V. T.,Arumugam, Selvakumar,Kulkarni, Aditya,Mondal, Kartik Chandra,Roy, Sudipta
supporting information, p. 6313 - 6318 (2020/09/02)
A Schiff-base nickel(II)-phosphene-catalyzed chemodivergent C-H functionalization and cyclopropanation of aromatic heterocycles is reported in moderate to excellent yields and very good regioselectivity and diastereoselectivity. The weak, noncovalent interaction between the phosphene ligand and Ni center facilitates the ligand dissociation, generating the electronically and coordinatively unsaturated active catalyst. The proposed mechanisms for the reported reactions are in good accord with the experimental results and theoretical calculations, providing a suitable model of stereocontrol for the cyclopropanation reaction.
A General Catalytic Route to Enantioenriched Isoindolinones and Phthalides: Application in the Synthesis of (S)-PD 172938
Ray, Sumit K.,Sadhu, Milon M.,Biswas, Rayhan G.,Unhale, Rajshekhar A.,Singh, Vinod K.
supporting information, (2019/01/21)
Chiral Br?nsted acid catalyzed enantioselective syntheses of isoindolinones and phthalides have been accomplished via tandem Mannich-lactamization and aldol-lactonization reactions, respectively. A variety of enantioenriched isoindolinones (up to 99% ee) and phthalides (up to 85% ee) containing α-diazoesters were afforded in excellent yields. Furthermore, a concise synthesis of (S)-PD 172938 has been demonstrated by using this protocol.
A General Catalytic Route to Enantioenriched Isoindolinones and Phthalides: Application in the Synthesis of (S)-PD 172938
Ray, Sumit K.,Sadhu, Milon M.,Biswas, Rayhan G.,Unhale, Rajshekhar A.,Singh, Vinod K.
supporting information, p. 417 - 422 (2019/01/23)
Chiral Br?nsted acid catalyzed enantioselective syntheses of isoindolinones and phthalides have been accomplished via tandem Mannich-lactamization and aldol-lactonization reactions, respectively. A variety of enantioenriched isoindolinones (up to 99% ee) and phthalides (up to 85% ee) containing α-diazoesters were afforded in excellent yields. Furthermore, a concise synthesis of (S)-PD 172938 has been demonstrated by using this protocol.
Synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives: Via a multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate
Shi, Taoda,Teng, Shenghan,Wei, Yajie,Guo, Xin,Hu, Wenhao
supporting information, p. 4936 - 4940 (2019/09/30)
We report a green synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives which are of potential value in medicinal chemistry. We are able to access spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives via a Cu(OTf)2-catalyzed or Cu(OTf)2/Rh2(OAc)4-cocatalyzed multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate. The reaction can be accomplished in good to excellent yields (60-99%), and the structure of products 6a and 6k was supported by X-ray crystallography. The catalyst Cu(OTf)2 can be recycled 4 times without a sharp loss of the yield of 6a. 6q can be easily synthesized in gram scale. In brief, the reaction is characterized by step economy, a harmless solvent, and a recyclable catalyst.
A chiral Br?nsted acid-catalyzed highly enantioselective Mannich-type reaction of α-diazo esters with in situ generated N -acyl ketimines
Unhale, Rajshekhar A.,Sadhu, Milon M.,Ray, Sumit K.,Biswas, Rayhan G.,Singh, Vinod K.
supporting information, p. 3516 - 3519 (2018/04/10)
A chiral phosphoric acid-catalyzed asymmetric Mannich-type reaction of α-diazo esters with in situ generated N-acyl ketimines, derived from 3-hydroxyisoindolinones has been demonstrated in this communication. A variety of isoindolinone-based α-amino diazo esters bearing a quaternary stereogenic center were afforded in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee). Furthermore, the synthetic utility of the products has been depicted by the hydrogenation of the diazo moiety of adducts.
In situ generation of nitrile oxides from copper carbene and tert -butyl nitrite: Synthesis of fully substituted isoxazoles
Chen, Rongxiang,Ogunlana, Abosede Adejoke,Fang, Shangwen,Long, Wenhao,Sun, Hongmei,Bao, Xiaoguang,Wan, Xiaobing
supporting information, p. 4683 - 4687 (2018/07/06)
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.
