Visible-light-driven radical 1,3-addition of selenosulfonates to vinyldiazo compounds
作者:Weiyu Li、Lei Zhou
DOI:10.1039/d1gc02036f
日期:——
radical 1,3-selenosulfonylation of vinyldiazo compounds with selenosulfonates, providing various γ-seleno allylic sulfones in good yields. This photochemical reaction was carried out at room temperature in an open flask using ethyl acetate as the solvent without any photocatalysts or additives. The control experiments corroborated that the 1,3-addition proceeded via a radical-chain propagation process. The
Intermolecular [5 + 1]-Cycloaddition between Vinyl Diazo Compounds and <i>tert</i>-Butyl Nitrite to 1,2,3-Triazine 1-Oxides and Their Further Transformation to Isoxazoles
作者:Luca De Angelis、Haifeng Zheng、Matthew T. Perz、Hadi Arman、Michael P. Doyle
DOI:10.1021/acs.orglett.1c02352
日期:2021.8.20
1,2,3-Triazine 1-oxides are formed by nitrosyl addition from tert-butyl nitrite to the vinylogous position of vinyl diazo compounds. This transformation, which is a formal intermolecular [5 + 1] cycloaddition, occurs under mild conditions, with high functional group tolerance and regioselectivity, and can be employed for late-stage functionalization. Upon heating at refluxing chlorobenzene temperature
Ethyl Lithiodiazoacetate: Extremely Unstable Intermediate Handled Efficiently in Flow
作者:Simon T. R. Müller、Tobias Hokamp、Svenja Ehrmann、Paul Hellier、Thomas Wirth
DOI:10.1002/chem.201602133
日期:2016.8.16
The generated ethyl lithiodiazoacetate is highly reactive and decomposes rapidly, even at lowtemperatures. Herein, we report a continuous flow protocol that overcomes the problems associated with the instantaneous decomposition of ethyl lithiodiazoacetate. The addition of ethyl lithiodiazoacetate to ketones provides direct access to tertiary diazoalcohols in good yields.
A novel halogenation/semipinacol rearrangement of alpha-diazo alcohol catalyzed by Lewis base has been developed through a carbene-free mechanism. This semipinacol transposition, initiated by an electrophilic halogenation (X = Cl(+), Br(+), and I(+)) of diazo carbon event, furnished a convenient synthetic route for the efficient synthesis of alpha-halo-quaternary ketones under mild conditions.
Inverse Electron Demand Diels–Alder-Type Heterocycle Syntheses with 1,2,3-Triazine 1-Oxides: Expanded Versatility
作者:Soumen Biswas、Luca De Angelis、Gildardo Rivera、Hadi Arman、Michael P. Doyle
DOI:10.1021/acs.orglett.2c04360
日期:2023.2.24
1,2,3-Triazine 1-oxides are remarkably effective substrates for inverse electron demand Diels–Alder reactions. Formed from vinyldiazoacetates via reaction with tert-butyl nitrite, these stable heterocyclic compounds undergo clean nucleophilic addition with amidines to form pyrimidines, with β-ketocarbonyl compounds and related nitrile derivatives to form polysubstituted pyridines and with 3/5-aminopyrazoles
1,2,3-三嗪 1-氧化物是逆电子需求 Diels-Alder 反应非常有效的底物。这些稳定的杂环化合物由乙烯基重氮乙酸酯通过与亚硝酸叔丁酯反应形成,通过干净的亲核加成与脒形成嘧啶,与 β-酮羰基化合物和相关腈衍生物形成多取代吡啶,与 3/5-氨基吡唑形成吡唑并 [1 ,5- a ]嘧啶,收率高。这些实际反应在室温下快速进行,是碱催化的,并提供多种结构修饰。