Novel ‘windscreen wiper’ cavity structures formed by the cycloaddition of N-substituted isoindoles onto molrac bis-alkenes

Abstract

Abstract A strong N -substituent effect is observed in the reaction of isoindoles with cyclobutene-1,2-diesters: N -alkyloxycarbonyl derivatives react to form adducts with bent-frame stereostructures; N -alkylisoindoles produce both extended-frame (stable) and bent-frame (unstable) stereoisomers, but require high-pressure conditions (10–15 kbar); N -acyl isoindoles fail to react. Reaction of N -benzyl tetrafluoroisoindole 6c with bis -alkene 13 produced the first ‘windscreen wiper’ N -bridged cavity compound 12 , the structure of which was confirmed by X-ray analysis.