Formation of 3-azabicyclo[3.3.1]non-3-enes: imino amides vs. imino alkenes
摘要:
An effective method for synthesising alkaloidlike compounds containing the 3-azabicyclo[3.3.1]non-3-ene core structure was successfully carried out in a stereo-selective manner via the bridged-Ritter reactions. Important optically active 6-alkyl(aryl)amido-4-alkyl(aryl)-2,2,6-trimethyl-3-azabicyclo[3.3.1]non-3-enes (imino amides) and 4-alkyl(aryl)-2,2,6-trimethyl-3-azabicyclo[3.3.1]nona-3,6-dienes (imino alkenes) were obtained in one step from (-)-beta-pinene and the respective nitriles in the presence of concentrated H2SO4. The relative compositions of these products were controlled by varying the reaction conditions. Kinetic studies were conducted to enable a mechanistic understanding of the reaction pathways.