An asymmetric [3+2] cycloaddition reaction ofN-2,2,2-trifluoroethylisatin ketimines and 3-alkenyl-5-arylfuran-2(3H)-ones was developed with 1 mol% thiourea–tertiary amine.
Formation of Allenyl Ketones, 3-Ethynylcoumarins, and Arylfurans, Furylfurans, and Furylthiophenes by Flash Vacuum Thermolysis of 3-Methylidenefuran-2(3<i>H</i>)-ones
作者:Rainer Koch、Hans Michael Berstermann、Curt Wentrup
DOI:10.1021/jo402139a
日期:2014.1.3
Flashvacuumthermolysis (FVT) of 3-methylidenefuran-2(3H)-ones 3 causes cheletropic extrusion of CO with formation of allenyl ketones 4. o-Chloro- and o-bromophenylmethylidenefuranones also afford allenyl ketones upon flashvacuumthermolysis, but in addition, 3-ethynylcoumarins 6 are formed via E/Z isomerization of the methylidenefuranones, cyclization, halogen atom migration, and HCl (HBr) elimination