Synthesis of 7-azabicyclo[4.3.1]decane ring system from tricarbonyl(tropone)iron via intramolecular Heck reactions

Abstract

The 7-azabicyclo[4.3.1]decane ring system, common to a number of biologically active alkaloids, was accessed from tropone (via its η4-diene complex with Fe(CO)3) in a short sequence of steps: 1) nucleophilic amine addition and subsequent Boc-protection; 2) photochemical demetallation of the iron complex; 3) intramolecular Heck reaction. Minor modifications to the protocol enabled access to the related 2-azabicyclo[4.4.1]undecane and 8-azabicyclo[5.3.0]decane ring systems, albeit in lower yield.