Catalyst-free one-pot domino reactions for selective synthesis of functionalized 2,8-oxazabicyclo[3.3.1]-nonanes and 5H-indeno[1,2-b]pyridin-5-ones

Abstract

A simple and efficient method for one-pot synthesis of new functionalized 2,8-oxazabicyclo-[3.3.1]nonanes from easily accessible 2-hydroxychalcones, 4-hydroxycoumarin/1,3-cyclohexandiones and aqueous ammonia under catalyst-free conditions is described. This reaction was probably achieved via an intermolecular Michael addition/amination/intramolecular bicyclization domino process. Hydroxy-containing 5H-indeno[1,2-b]pyridin-5-ones were obtained when five-membered 1,3-indandione was employed in this reaction.