Efficient synthesis of novel thieno[3,2-b]-, [2,3-c]- and [3,2-c]pyridones by Sonogashira coupling of bromothiophenes with terminal alkynes and subsequent intramolecular C–N bond-forming reaction
作者:Viktor O. Iaroshenko、Sajid Ali、Tariq Mahmood Babar、Muhammad S.A. Abbasi、Vyacheslav Ya Sosnovskikh、Alexander Villinger、Andrey Tolmachev、Peter Langer
DOI:10.1016/j.tet.2013.02.069
日期:2013.4
Sonogashira conditions (PdCl2(PPh3)2, CuI) followed by subsequent addition of amines or ammonium to the intermediate thienyl acetylenes represents a novel access to a wide range of thieno[3,2-b]-, [2,3-c]-, and [3,2-c]pyridones under basic conditions and in excellent yields.
在Sonogashira条件下,使用三乙胺或二异丙基胺(PdCl 2(PPh 3)2,CuI)将溴噻吩与末端炔烃偶联,随后将胺或铵加到中间的噻吩基乙炔中,代表了广泛获得噻吩并[[thiono]]的新途径。 3,2- b ]-,[2,3- c ]-和[3,2- c ]吡啶酮在碱性条件下且收率很高。
Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily
Regioselective Synthesis of 4‐Aryl‐1,3‐dihydroxy‐2‐naphthoates through 1,2‐Aryl‐Migrative Ring Rearrangement Reaction and their Photoluminescence Properties
scaffold and that show photoluminescence emission from solid state as well as in solutions, were selectively synthesized from brominated lactol silyl ethers through the 1,2-aryl-migrative ringrearrangementreaction.
Arenediazonium o-benzenedisulfonimides can be used as efficient reagents in Sonogashiracoupling reactions. In this work, reactions were carried out in DMSO under very mild conditions (without copper or phosphanes), and gave rise to arylated alkynes in good to excellent yields (25 examples, average yield 83 %). o-Benzenedisulfonimide could be recovered from all the reactions in yields of >80 %, so