Electrophilic iodonium-ion mediated spirocyclization of 4-(5-(arylethynyl)pyrimidin-4-yl)phenols enroute to spiro[cyclohexa[2,5]diene-1,7′-cyclopenta[d]pyrimidin]-4-one core

Abstract

Novel iodonium-ion mediated spirocyclization of 4-(5-(arylethynyl)pyrimidin-4-yl)phenols leading to spiro[cyclohexa[2,5]diene-1,7′-cyclopenta[d]pyrimidin]-4-one core was developed. This sequence, based commercially available reagents starts with acid-catalyzed electrophilic alkylation of phenols with 5-bromopyrimidine. Subsequently, an oxidation, palladium-catalyzed Sonogashira cross-coupling reaction and electrophilic spirocyclization, allowed to target product with good yields and simple synthetic protocols.