Direct synthesis of 2,3-dihydroperimidine derivatives via dehydrogenative C-N coupling using a recyclable Fe catalyst.

We report here an efficient and sustainable protocol for the direct synthesis of 2,3-dihydroperimidine derivatives via dehydrogenative C-N coupling, utilizing a recyclable Fe single-atom catalyst supported on nitrogen-doped carbon (Fe1-N-C). The catalyst was synthesized by encapsulating ferrocene within the ZIF-8 framework, followed by pyrolysis. The catalyst exhibited excellent activity, stability, and recyclability, facilitating the transformation of diverse primary alcohols, including aryl/heteroaryl methanol and aliphatic alcohols, into the desired products in moderate to good yields. To delineate the mechanism, several control experiments were performed, revealing the formation of aldehyde as the intermediate, which subsequently underwent annulation with naphthalene-1,8-diamine. Additionally, the gram-scale synthesis further showcased the versatility of the catalyst as well as the protocol.