Functionalization at C-2 and C-5 of N-benzenesulfonyl-4-azaindole 1 was performed by lithiation reactions and original palladium-catalyzed chemistry. It led to very useful new substituted 4-azaindole derivatives in fair to high yields.
Relay Catalysis To Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
作者:Sasha Sundstrom、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/acs.orglett.9b04584
日期:2020.2.21
Organocatalysis was shown to facilitate conjugate additions to vinylogousesters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline)
monobromoalkene, a combination of hydrosilylation/vinylsilane hydrolysis and a palladium-catalyzed semi-hydrogenation step, using DMF/KOH as the hydrogen source. Our studies led us to prepare a series of diarylacetylene derivatives via a Sonogashira coupling reaction, and also to find out a copper-free basic cyclization leading to benzo[b]thiophenes. The final choice for the synthesis method of 1 strongly depends
研究了几种制备(Z)三甲氧基苯乙烯衍生物1的方法。在发现Wittig反应导致不满意的结果后,考虑了三种不同的策略:使用DMF / KOH作为氢源的Suzuki偶联与立体定义的单溴烯烃,氢化硅烷化/乙烯基硅烷水解和钯催化的半氢化步骤的组合。我们的研究使我们通过Sonogashira偶联反应制备了一系列二芳基乙炔衍生物,并且发现了无铜的碱性环化反应,从而生成了苯并[ b ]噻吩。1的合成方法的最终选择 强烈依赖于目标化合物,但通常应优先选择避免使用有毒锡还原剂的半氢化反应。
Metal‐Free Oxidative Cross Coupling of Indoles with Electron‐Rich (Hetero)arenes
作者:Paola Caramenti、Raj Kumar Nandi、Jerome Waser
DOI:10.1002/chem.201802142
日期:2018.7.17
A new method for the synthesis of bi‐heteroaryls is reported, based on the umpolung of indoles with benziodoxol(on)e hypervalentiodinereagents (IndoleBX). The oxidative coupling of IndoleBX with an equimolar amount of electron‐rich benzenes, indoles, pyrroles, and thiophenes proceeded under mild transition‐metal‐free conditions. Functionalized non‐symmetrical bi‐indolyl heterocycles were accessed