Generation and inter- and intra-molecular trapping of isoindenones (inden-2-ones)

Abstract

Inden-2-one and some simple derivatives are smoothly generated by reaction of caesium fluoride with 1-bromo-2-tert-butyldimethylsilyloxyindenes and they can be efficiently trapped in both intra- and inter-molecular additions; the intramolecular additions proceed with exo-addition of the tether, in contrast to the intermolecular additions and intramolecular additions to 2-benzopyran-3-ones.