Stereoselective cyclopropanation of enamides via C–C bond cleavage of cyclopropenes

This work describes a straightforward protocol for the stereoselective synthesis of vinylcyclopropylamides in high E / Z and syn / anti ratios by cyclopropanation of N -tosyl substituted enamides with cyclopropenes in the presence of a rhodium catalyst under very mild reaction conditions. The obtained small rings are further exploited to undergo regioselectively oxidative ring-opening reactions with silver and copper co-catalysts to provide conjugated 1,3-dienyl aldehydes in moderate to good yields. Several vinylcyclopropylamides exhibit good antibacterial activities against Xanthomonas oryzae pv. oryzae ( Xoo ).