2H-Chromenes from salicylaldehydes by a catalytic petasis reaction
The Petasis condensation of vinylic or aromatic boronic acids, aromatic aldehydes, and amines is assisted by a hydroxy group adjacent to the aldehyde moiety. The products derived from salicylaldehydes and vinylboronic acids undergo cyclization to 2H-chromene compounds with ejection of amine upon heating. A catalytic preparation of 2H-chromenes using resin-bound amine is reported, allowing the convenient incorporation of a variety of components.
Wang
Q
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Finn
MG