Modular Preparation of 5-Halomethyl-2-oxazolines via PhI(OAc)2-Promoted Intramolecular Halooxygenation of N-Allylcarboxamides
摘要:
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.
Microwave-assisted, Mo(CO)6-mediated, palladium-catalyzed amino-carbonylation of aryl halides using allylamine: from exploration to scale-up
作者:Prasad Appukkuttan、Linda Axelsson、Erik Van der Eycken、Mats Larhed
DOI:10.1016/j.tetlet.2008.07.053
日期:2008.9
Palladium-catalyzed aminocarbonylations of various (hetero)aryl halides with allylamine usingMo(CO)6 as a solid, in situ CO source, were explored. Microwave-enhanced conditions proved to be highly useful in promoting the conversions in a mere 10–20 min with various (hetero)aryliodides, bromides and chlorides. The scale-up of a microwave-enhanced aminocarbonylation to 25 mmol scale was performed successfully
We report a new air‐stable PdI dimer, [Pd(μ‐I)(PCy2tBu)]2, which triggers E‐selective olefin migration to enamides and styrene derivatives in the presence of multiple functional groups and with complete tolerance of air. The same dimer also triggers extremely rapidC−Ccoupling (alkylation and arylation) at roomtemperature in a modular and triply selective fashion of aromatic C−Br, C−OTf/OFs, and
我们报告了一种新的空气稳定的Pd I二聚体[Pd(μI)(PCy 2 t Bu)] 2,它在存在多个官能团且具有完全耐受性的情况下触发E-选择性烯烃向酰胺和苯乙烯衍生物的迁移空气 同一二聚体还可以在室温下以模块化和三重选择性的方式在聚(假)卤代芳烃中以芳族C-Br,C-OTf / OF和C-Cl键的形式快速触发C-C偶联(烷基化和芳基化)在具有邻位C-OTf的取代基的底物上显示出比以前的Pd I二聚体更好的活性。
Electrochemical oxidative cyclization of olefinic carbonyls with diselenides
作者:Zhipeng Guan、Yunkun Wang、Huamin Wang、Yange Huang、Siyuan Wang、Hongding Tang、Heng Zhang、Aiwen Lei
DOI:10.1039/c9gc02665g
日期:——
The tandem cyclization of olefinic carbonyls with easily accessible diselenides facilitated by electrochemical oxidation has been successfully developed, which provides an environmentally friendly method for the construction of C–Se and C–O bonds simultaneously. A series of seleno dihydrofurans and seleno oxazolines, bearing fragile heterocycles, subtle C–I bonds and supernumerary vinyl groups, were
CuBr 2 -promoted intramolecular bromocyclization of N-allylamides and aryl allyl ketone oximes
作者:Chun-Hua Yang、Zhong-Qi Xu、Lili Duan、Yue-Ming Li
DOI:10.1016/j.tet.2017.10.025
日期:2017.11
A new and easy-to-perform route to 2-oxazolines amd isoxazolines was reported. Using CuBr2 as both the bromide source and the reaction promoter, bromocyclization of N-allylamides and allyl ketone oximes proceeded readily, leading to oxazolines and isoxazolines in good to excellent yields.
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