A copper-catalyzed domino radical cyclization route to benzospiro-indolizidinepyrrolidinones

Abstract

In this Letter the synthesis of benzospiro-indolizidinepyrrolidinones is described by a domino atom transfer radical cyclization reaction using a copper catalyst. The structure of one of the products was established by single crystal X-ray diffraction. The investigated precursors, bearing a homo allyl substituent on the N-indole, result in a 5- exo- trig, followed by a 6- endo- trig cyclization. When the N-indole is substituted with an allyl group, only the spiro-cyclization occurs.