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Generation of Sulfonyl Radicals from Aryldiazonium Tetrafluoroborates and Sulfur Dioxide: The Synthesis of 3‐Sulfonated Coumarins
Author(s) -
Zheng Danqing,
Yu Jiyao,
Wu Jie
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201607292
Subject(s) - dabco , sulfonyl , chemistry , radical , tandem , aryl , catalysis , combinatorial chemistry , sulfur , sulfur dioxide , aryl radical , organic chemistry , photochemistry , materials science , alkyl , composite material
A catalyst‐free approach for the generation of sulfonyl radicals from aryldiazonium tetrafluoroborates in the presence of DABCO⋅(SO 2 ) 2 is realized. The combination of aryldiazonium tetrafluoroborates, DABCO⋅(SO 2 ) 2 , and aryl propiolates affords 3‐sulfonated coumarins in good to excellent yields. This tandem reaction process involves radical addition, spirocyclization, and 1,2‐migration of esters. Additionally, the in situ diazotization of a number of anilines allows the directional synthesis of desired 3‐sulfonated coumarins in a one‐pot, two‐step process.