A Short, Gram-Scale Synthesis of 2,5-Disubstituted Furans
作者:Stanley Chang、Saheena Desai、Daniel B. Leznoff、Nabyl Merbouh、Robert Britton
DOI:10.1002/ejoc.201300305
日期:2013.6
Feist–Benary furansynthesis has been developed that involves a lithium aldol reaction between a methyl ketone and an α-chloroaldehyde followed by a thermally induced tetrahydrofuran formation/dehydration sequence and affords 2,5-disubstitutedfurans in good overall yield. This process is demonstrated on multigram scale and is amenable to the production of symmetric or asymmetric furans that incorporate
Catalytic Generation of Vinylthionium Ions. (4 + 3)-Cycloadditions and Friedel–Crafts Alkylations
作者:Michael Topinka、Rama Rao Tata、Michael Harmata
DOI:10.1021/ol502019n
日期:2014.9.5
vinylthionium ions. These species react with dienes, primarily substituted furans, to give products of either (4 + 3)-cycloaddition or Friedel–Crafts alkylation. The results are rationalized on the basis of a stepwise mechanism in which the relative rates of ring closure versus proton loss in the intermediateσ-complex determine the course of the reaction.
resemble each other; on the other hand, the n-hexyl derivative displayed a slightly red-shifted and broader spectrum. The absolute quantum yield depended on the transition dipolemoments because of the packing patterns and crystal rigidity. The n-propyl derivative demonstrated the highest quantum yield of Φf = 0.85 among the tetra(alkyl)anthracenes.
5‐dialkylfurans as starting materials (alkyl=methyl to hexyl). Surprisingly, the solid‐state color of the tetracenes ranges through yellow, orange, and red. Both yellow and red solids are obtained for the butyl derivative. Opticalproperties in solution show no marked differences; however, those in the solid state show characteristics that vary with alkyl side‐chain length: methyl, propyl, and pentyl derivatives
Nickel catalysis synthesis of 2,5-disubstituted furans from aryl (alkyl) iodide
作者:Zhongqiang Sun
DOI:10.1080/10426507.2023.2249576
日期:2024.1.2
A new methodology using various aryl(alkyl)iodides and CaC2 as coupling partners has been developed for the successful preparation of 2,5-disubstitutedfurans in good to excellent yields. The broad...