reported an efficient and sustainable intramolecular electrochemical cyclization of N-allylcarboxamides for the synthesis of various halogenated oxazolines. This method was conducted in a simple undivided cell by employing lithium halogen salts as redox media and halogen sources. A wide range of oxazolines, including five- and six-membered heterocycles, and iodo-, bromo-, and chloro-methyl oxazolines were
haloheterocyclization of N-alkenylamides using bulk and common chemicals such as 1,2-dihaloethanes as halogenating reagents are less studied. Herein, we have developed an electrochemical intramolecular haloheterocyclization of N-alkenylamides to prepare 2-oxazolines, 2-thiazolines, 1,3-oxazines and isoxazolines using readily available 1,2-dihaloethanes as halogenating reagents. This protocol is a convergent
Neighboring Groups in Addition. V.<sup>1</sup> The Benzamido Group in 3-Benzamidopropene<sup>2</sup>
作者:Leon Goodman、S. Winstein
DOI:10.1021/ja01574a052
日期:1957.9
Modular Preparation of 5-Halomethyl-2-oxazolines via PhI(OAc)<sub>2</sub>-Promoted Intramolecular Halooxygenation of <i>N</i>-Allylcarboxamides
作者:Gong-Qing Liu、Chun-Hua Yang、Yue-Ming Li
DOI:10.1021/acs.joc.5b01832
日期:2015.11.20
A new method for the construction of oxazoline moiety was detailed. Using (diacetoxyiodo)benzene (PIDA) as the reaction promoter and halotrimethylsilane as the halogen source, intramolecular halooxygenation and halothionation of N-allylcarboxamides/N-allylcarbothioamides proceeded readily, leading : to the corresponding 5-halomethyloxazolines/5-halomethylthiazolines in good to excellent isolated yields. The 5-halomethyl products could be converted to different derivatives via conventional nucleophilic substitution methods. The reactions were carried out using easily available starting materials, and did not need harsh reaction conditions. All these features made this reaction a viable method for the construction of different oxazoline and thiazoline structures.