Synthetic approaches to nortropanes and nortrop-6-enes; intramolecular displacement by nitrogen in 7-membered rings
摘要:
The synthesis of simple nortropane and nortrop-6-ene derivatives from cyclohepta-1,3-diene is described. The key intermediates are trans-1-amino-4-chloro-cycloheptanes and -cyclohept-2-enes which are derived efficiently from the corresponding cis-amino-alcohols and undergo intramolecular cyclisation. Corresponding derivatisation of cyclohexa- and cycloocta-1,3-dienes is explored and attempts to achieve Pd-catalysed cyclisation of 1-amino-4-acetoxy-derivatives is described. Nitrogen inversion data for selected nortropane derivatives are included.
catalytic efficiency in the Ir-catalyzed stereoselective hydrogenation of various ketones to afford corresponding stereodefined alcohols with excellent results (full conversions, cis/trans >99:1, and 83% → 99% ee, TON up to 500 000). Control experiments have shown that −OH and −NH groups played a key role in this stereoselective hydrogenation.