1,3-Dipolar Cycloaddition of Nitrile Imine with Carbon Dioxide: Access to 1,3,4-Oxadiazole-2(3<i>H</i>)-ones
作者:Chun-Xiao Guo、Wen-Zhen Zhang、Ning Zhang、Xiao-Bing Lu
DOI:10.1021/acs.joc.7b00963
日期:2017.7.21
Efficient synthesis of 1,3,4-oxadiazole-2(3H)-one was achieved by CsF/18-crown-6 mediated 1,3-dipolar cycloaddition of nitrile imine and 2.0 MPa of CO2. CsF/18-crown-6 played a key role in enhancing the reactivity of CO2 as a 1,3-dipolarophile. The practical utility of this transition-metal-free approach to 1,3,4-oxadiazole-2(3H)-one is highlighted by the convenient synthesis of a commercial herbicide
Freund; Goldsmith, Chemische Berichte, 1888, vol. 21, p. 2461
作者:Freund、Goldsmith
DOI:——
日期:——
Kametani,T. et al., Journal of Heterocyclic Chemistry, 1970, vol. 7, p. 821 - 829
作者:Kametani,T. et al.
DOI:——
日期:——
Stansfield, Journal of the Chemical Society, 1958, p. 4781
作者:Stansfield
DOI:——
日期:——
The reaction of sydnones with bromine in acetic anhydride revisited: a new route to 5-substituted-3-aryl-1,3,4-oxadiazol-2(3H)-ones from N-aryl-N-bromocarbonylhydrazines
作者:Jonathan Michael Tumey、Thijs Gerritsen、Jimmy Klaasen、Karunakar Reddy Madaram、Kenneth Turnbull
DOI:10.24820/ark.5550190.p010.488
日期:——
The reaction of 3-phenylsydnone with bromine in aceticanhydride to form 5-methyl-3-phenyl-1,3,4-oxadiazol2(3H)-one has been reexamined and improved. A new mechanism involving a bromocarbonylhydrazine species is proposed and its intermediacy is supported by the observation that it reacts with aceticanhydride to yield the corresponding 1,3,4-oxadiazol-2(3H)-one. The process has been expanded to the