| Indoles and indolizines are two important nitrogenous aromatic heterocyclic compounds,that are widely used in medicine,pesticide and other fields due to their unique molecular structure.It is noteworthy that the five-membered azacyclic indoles bind to the anomeric carbon of glycopyranoses via a C-C bond to form indole-C-glycosides,which have a wide range of biological activities.Therefore,we have developed a palladium-catalyzed method for synthesis of 3-indole-C-glycosides from 1-iodoglycals and o-alkynylanilines via tandem heterocyclic/C-glycosylation reactions.In addition,the construction of 3-indolyl-C-glycosides was further studied.The regional and stereoselective construction of C-glycoside was completed by tandem cyclization reaction of glycals and o-alkynylanilines under palladium catalysis.This method provides a new method for the synthesis of 3-indolyl-α-C-glycosides.At last,due to the significant biological activity of indolizine structures in various natural products and drugs,most of the current construction methods of indolizine compounds by metal-catalyzed cycloisomerization are limited to the formation of a single C-N bond or a C-N bond and a C-C bond.Therefore,we developed a palladium-catalyzed arylation/heteroarylation of alkene double bonds using propargylic pyridines and aryl halide-tethered alkenes as raw materials through intramolecular carbon palladium and cycloisomerization.This method can effectively construct one C-N bond and two C-C bonds,and quickly synthesize the complex structure of the molecule,providing a way for the efficient synthesis of oxindole,azaoxindole,dihydrobenzopyran,indole and benzofuran-containing indolizines. |
