An Efficient Approach for Monofluorination via Aqueous Fluorolactonization Reaction of 2,3-Allenoic Acids with Selectfluor
摘要:
[GRAPHICS]We have developed a convenient method for the efficient monofluorination via the electrophilic fluorocyclization reaction of 2,3-allenoic acids with Selectfluor in MeCN in the presence of 10 equiv of H2O or even in pure water to afford beta-fluorobutenolides in moderate to high yields.
Efficient Assembly of Chromone Skeleton from 2,3-Allenoic Acids and Benzynes
作者:Guobi Chai、Youai Qiu、Chunling Fu、Shengming Ma
DOI:10.1021/ol202076c
日期:2011.10.7
Chromone derivatives were synthesized from 2,3-allenoicacids and benzynes in moderate to excellent yields under mild conditions. Instead of the cyclic conjugate addition of the intermediate A formed by the nucleophilic addition of allenoic acid with benzyne, this intermediate undergoes 1,2-addition with the carbonyl group, which was followed by the ring opening, conjugate addition, and protonolysis