(C6F5)(3)B Catalyzed One-Pot Synthesis of Benzo[b]Cyclopenta[e][1,4]Oxazin-2(1H)-One and Thiazin-2(1H)-One Derivatives from Furan-2-yl(Phenyl)Methanol and 2-Aminophenol/Thiophenol

An efficient (C6F5)(3)B catalyzed method has been developed for the synthesis of benzo[b]cyclopenta[e][1,4]oxazin-2(1H)-one and thiazin-2(1H)-one derivatives from furan-2-yl(phenyl)methanol (1) and 2-aminophenol/thiophenol (2) under reflux in acetonitrile. This reaction proceeds through an aza-Piancatelli rearrangement/Michael reaction in one-pot. This strategy provides a facile and rapid access to benzo[b]cyclopenta[e][1,4]oxazin-2(1H)-one and thiazin-2(1H)-one derivatives (3a-l) in good to high yields under mild conditions. Several advantages, such as simple reaction procedure, low catalyst loading, broad substrate scope, easy product isolation, high functional group tolerance, and short reaction time make this strategy more attractive.