Functionalized3-bromocoumarins 2 have been prepared by a simpleone-pot bromination/Wittig/cyclization tandem process from methyl (triphenylphosphoranylidene)acetate, N-bromosuccinimide and a series of 2-hydroxybenzaldehydes. Owing to the commercial availability of salicylaldehyde derivatives, this approach offers such a diverse range of compounds that it fulfills the recent demand for the generation
Conversion of 3-Bromo-2<i>H</i>-coumarins to 3-(Benzofuran-2-yl)-2<i>H</i>-coumarins under Palladium Catalysis: Synthesis and Photophysical Properties Study
An intriguing conversion of 3-bromo-2H-coumarins to 3-(benzofuran-2-yl)-2H-coumarins under palladium catalysis is reported. The process involves, from only one single starting material, three transformations and two bond formations in one pot: C–C bond formation via C–H activation and C–O bond formation through 2H-coumarin-to-benzofuran ring contraction under palladium catalysis. Moreover, the photophysical
An Expeditious Copper-Catalyzed Access to 3-Aminoquinolinones, 3-Aminocoumarins and Anilines using Sodium Azide
作者:Samir Messaoudi、Jean-Daniel Brion、Mouâd Alami
DOI:10.1002/adsc.201000149
日期:——
3‐bromocoumarins, respectively, has been achieved. The reaction conditions involve the use of copper powder as the catalyst, eco‐friendly ethanol as the solvent in the presence of pipecolinic acid as the ligand and ascorbic acid as the additive. The efficiency of this practical method was demonstrated in the synthesis of various anilines.
一种有效的铜催化的原位C(SP 2) NH 2键形成来提供一系列3-氨基喹啉-2(1 H ^) -酮和由3- bromoquinolinones和3- bromocoumarins 3-氨基香豆素,分别,一直实现。反应条件包括使用铜粉作为催化剂,使用生态友好型乙醇作为溶剂,并以胡椒酸作为配体,抗坏血酸作为添加剂。在各种苯胺的合成中证明了这种实用方法的效率。
Efficient synthesis of 4-sulfanylcoumarins from 3-bromo-coumarins<i>via</i>a highly selective DABCO-mediated one-pot thia-Michael addition/elimination process
作者:Vitor B. Mostardeiro、Marina C. Dilelio、Teodoro S. Kaufman、Claudio C. Silveira
DOI:10.1039/c9ra09545d
日期:——
was developed. The transformation took place with aromatic and aliphatic thiols as well as with α,ω-dithiols, affording the expected products in very good to excellent yields. Simple and convenient ways to access4-((ω-mercaptoalkyl) thio)coumarins and the dimeric 4,4′-(alkane-1,4-diylbis(sulfanediyl))bis(coumarins) were also devised with the use of α,ω-alkanedithiols in different ratios with regards