Transformation of reactive isochromenylium intermediates to stable salts and their cascade reactions with olefins.
Transformation of reactive isochromenylium intermediates to the corresponding storable and stable reagents has been achieved, and a number of isochromenylium tetrafluoroborates (ICTBs, 1) have been conveniently prepared and characterized. Direct metal-free treatment of isochromenylium tetrafluoroborate 1a with olefins afforded a variety of polycyclic frameworks 4 via mild cascade reactions. Starting from the prefunctionalized o-alkynylbenzaldehydes, a one-pot metal-free procedure of intramolecular cascade annulation to 2,3-dihydrophenanthren-4(1H)-one derivatives was also developed.
Hu
Zhi-Long
ZL
State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Qian
Wen-Jian
WJ
Wang
Sheng
S
Wang
Shaozhong
S
Yao
Zhu-Jun
ZJ
D000388:Air; D000475:Alkenes / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D012492:Salts / Q000737:chemistry*
D000475:Alkenes; D012492:Salts