[2 + 2 + 1] Heteroannulation of Alkenes with Enynyl Benziodoxolones and Silver Nitrite Involving C≡C bond Oxidative Cleavage: Entry to 3-Aryl-Δ<sup>2</sup>-isoxazolines
作者:Cheng-Yong Wang、Fan Teng、Yang Li、Jin-Heng Li
DOI:10.1021/acs.orglett.0c01285
日期:2020.6.5
A copper-catalyzed [2 + 2 + 1] heteroannulation of alkenes with enynyl benziodoxolones and AgNO2 involving oxidative cleavage of the C≡C bond promoted by cooperative Zn(OTf)2, KOAc, and 4 Å MS for producing 3-aryl Δ2-isoxazolines is reported. Mechanistic studies indicate that AgNO2 serves as the N/O two-atom unit source, enabling the formation of three bonds through NO2 addition across the C≡C bond
Visible-light-mediated generation of nitrile oxides for the photoredox synthesis of isoxazolines and isoxazoles
作者:Thomas D. Svejstrup、Wojciech Zawodny、James J. Douglas、Damon Bidgeli、Nadeem S. Sheikh、Daniele Leonori
DOI:10.1039/c6cc06029c
日期:——
Visible-light photoredox catalysis enables the synthesis of biologically relevant isoxazolines and isoxazoles from hydroxyimino acids. The process shows broad functional group compatibility and mechanisitic and computational studies support a visible-light-mediated...
A Convenient Preparative Method of Nitrile Oxides by the Dehydration of Primary Nitro Compounds with Ethyl Chloroformate or Benzenesulfonyl Chloride in the Presence of Triethylamine
nitrile oxides (MeOCOC≡N→O, PhC≡N→O, and EtC≡N→O) were effectively generated in situ by dehydration of the corresponding primary nitro compounds (RCH2NO2) with PhSO2Cl or ClCOOEt in the presence of triethylamine. Various cycloadducts were prepared by the reaction of them with dipolarophiles. Some advantages of these methods are described in comparison with other known methods.
O-Ethoxycarbonyl hydroximoyl chloride serves as a stable precursor for nitrileoxide and is converted into the 1,3-dipole when heated under reflux in pyridine.
O-乙氧羰基羟肟酰氯作为腈氧化物的稳定前体,在吡啶中回流加热时转化为 1,3-偶极子。
Electrochemical Synthesis of Isoxazolines: Method and Mechanism
作者:Samuel D. L. Holman、Alfie G. Wills、Neal J. Fazakerley、Darren L. Poole、Diane M. Coe、Leonard A. Berlouis、Marc Reid
DOI:10.1002/chem.202103728
日期:2022.3
Isoxazolines without the [3+2]: An electrochemical method for the synthesis of isoxazoline cores is presented. Both aryl and more challenging alkyl aldoximes are converted to the desired isoxazoline through an electrochemically enabled regio- and diastereoselective reaction with electron-deficient alkenes. Supporting analyses from kinetic (time-course) modelling and density functional theory support