Synthesis of polycyclic xanthenes and furans via palladium-catalyzed cyclization of polycyclic aryltriflate esters
作者:Ji-Quan Wang、Ronald G Harvey
DOI:10.1016/s0040-4020(02)00534-3
日期:2002.7
Palladium-catalyzed cyclization of polycyclic aromatic o-(arylmethyl)phenol triflate esters takes place with unexpected sulfur–oxygen bond cleavage to furnish polycyclic xanthenes. These are the first examples of Pd-catalyzed cross-coupling of aryl triflate esters with arenes to form diaryl ethers. In contrast, analogous palladium-catalyzed cyclization of polycyclic o-(aryloxy)phenol triflate esters
A ring-closurereaction by thermal dediazoniation of 2-substituted benzenediazonium tetrafluoroborates in imidazolium-based ionic liquids was investigated. Dediazoniation of 2-(4-R-benzoyl)benzenediazonium tetrafluoroborates (R = H, Me, OMe, Cl) in ionic liquid [BMIM][TfO] gave 3-R-9-fluorenones as ring-closure products and 2-(4-R-benzoyl)phenyl trifluoromethanesulfonates as substitution products.