posted on 2024-01-22, 16:41authored byQuan Liu, Feng Wang, Zeng-Yang He, Hui Zhang, Jia-Rong Wang, Qing-Hai Li, Ze Zhang, Hui Xu
A novel
and flexible domino reaction of aurones with pyridin-2-yl
active methylene compounds promoted by I2/BF3 has been developed to afford spirodihydroindolizines and indolizines
in a controllable manner. When the reaction was performed in 1,2-dichloroethane
at 80 °C, a variety of spirodihydroindolizines were obtained,
whereas it almost exclusively provided a series of indolizines when
the reaction was performed in a mixed solvent of 1,2-dichloroethane
and N,N-dimethylformamide at a relatively
higher temperature of 100 °C. Being metal-free, excellent product
selectivity, high atom economy, good functional group tolerance, and
feasibility for large-scale synthesis are the salient features of
the developed methodology.