已经开发了使用炔烃的铜催化分子内NH / CH环合反应。各种稠密官能化的杂环,如吡咯并[1,2- a ]吲哚,吲哚并[1,2 - c ]喹唑啉-2-酮,恶唑并[3,4- a ]吲哚和咪唑[1,5-由于苯胺部分,连接子部分和炔烃部分具有高度模块化的特征,因此以原子和分步经济的方式合成了α ]吲哚。通过简单地改变从二氧化剂叔将过氧化叔丁基(DTBP)转化为2,2,6,6-四甲基哌啶-1-氧基(TEMPO),该反应很容易转化为氨氧化途径,该途径从TEMPO夺取一个氧原子以生成5-芳酰基吡咯2个 机理实验表明,乙烯基自由基参与了该反应,而酰胺基自由基引发的自由基级联反应可能是造成这种转变的原因。
An electrochemical synthesis of functionalized (aza)indolinesthrough dehydrogenative [3+2] annulation of arylamines with tethered alkenes has been developed. Previous reported syntheses through similar inter‐ and intramolecular annulation reactions required noble‐metal catalysts and are mostly limited to terminal alkenes or 1,3‐dienes. The electrosynthesis employs the easily available and inexpensive
Herein, we demonstrated that 2-alkynyldimethylamines easily cyclize in EtOH according to a 5-endo-dig annulation into 2-substitutedindoles without the aid of any additives or any metal catalysts to activate the triple bond. Thus, a variety of functionalized 2-styrylindoles, 2-arylindoles, 2-alkynylindoles, and 2-alkylindoles were prepared in high to excellent yields according to an environmentally
Synthesis and Catalytic Activity of Coumarin‐ and Chrysin‐Tethered Triazolylidene Gold(I) Complexes
作者:Francisco J. Ruiz‐Mendoza、Daniel Mendoza‐Espinosa、Simplicio González‐Montiel
DOI:10.1002/ejic.201800921
日期:2018.11.15
chrysin‐functionalized triazolium salts (2,3) have been synthesized stepwise via copper catalyzed alkyne–azide cycloaddition and N‐alkylation procedures. Their one‐pot deprotonation with KHMDS in presence of AuCl(SMe2) allowed for the preparation of the corresponding triazolylidene gold(I) complexes (4–6) in high yields (75–92 %). All new compounds were fully characterized by means of 1H and 13C NMR spectroscopy
一系列空间位作保香豆素(1)和白杨素官能化的三唑鎓盐(2,3)已经通过铜催化炔叠氮化物环加成和合成逐步Ñ烷基化方法。他们在AuCl(SMe 2)存在下用KHMDS进行一锅式去质子反应,从而可以高产率(75-92%)制备相应的三唑基亚金(I)配合物(4-6)。所有新化合物均通过1 H和13 C NMR光谱,FT-IR,元素分析以及在三唑F,三唑鎓1和金络合物4的情况下得到充分表征。,通过单晶X射线衍射。通过几种容易获得的苯胺的分子内加氢胺化反应,将新的三唑基亚金配合物(4-6)作为吲哚衍生物合成中的前催化剂进行了测试。
Electrochemical Synthesis of Imidazo-Fused N-Heteroaromatic Compounds through a C−N Bond-Forming Radical Cascade
We have developed a unified strategy for preparing a variety of imidazo‐fused N‐heteroaromatic compoundsthrough regiospecific electrochemical (3+2) annulation reaction of heteroarylamines with tethered internal alkynes. The electrosynthesis employs a novel tetraarylhydrazine as the catalyst, has a broad substrate scope, and obviates the need for transition‐metal catalysts and oxidizing reagents.
electrocatalytic strategy for the cyclopropanation of activemethylenecompounds, employing an organic catalyst. The method shows a broad substrate scope and excellent scalability, requires no metal catalyst or external chemical oxidant, and provides convenient access to several types of cyclopropane-fused heterocyclic and carbocyclic compounds. Mechanistic investigations suggest that the reactions