Metal-mediated cyclization of aryl and benzyl glycidyl ethers: a complete scenario.
Enantiomerically pure aryl and benzyl glycidyl ethers undergo stereospecific cyclizations leading to 3-chromanols or to tetrahydrobenzo[c]oxepin-4-ols under mild conditions in the presence of a catalytic amount of FeBr3/3AgOTf. The same processes are also mediated, albeit in a much less efficient manner, by AuCl3/3AgOTf. The set of active mediators in this group of processes (BF3 x Et2O, FeBr3, FeBr3/3AgOTf, AuCl3/3AgOTf) shows its nature as Friedel-Crafts reactions and disfavors the intermediacy of arylgold species.
Marcos
Rocío
R
Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans 16, 43007 Tarragona, Spain.
Rodríguez-Escrich
Carles
C
Herrerías
Clara I
CI
Pericàs
Miquel A
MA