The first example of direct cyclopropylation of arylamines at the 2-position with magnesium cyclopropylidenes

Treatment of magnesium cyclopropylidenes, which were generated from 1-chlorocyclopropyl phenyl sulfoxides with isopropylmagnesium chloride in THF at −78 °C, with N-lithio arylamines gave arylamines cyclopropylated at the 2-position in moderate to good yields. Use of the magnesium cyclopropylidenes having at least one substituent was found to be essential to this cyclopropylation. This procedure offers a novel synthesis of arylamines having a cyclopropane ring at the 2-position directly from arylamines.