Abstract
Highly chemo- and regioselective synthesis of 2-alkylpyridine N-oxides from pyridine N-oxides and cyclic ethers has been developed through copper-catalyzed CDC reactions using CuO as the catalyst under mild reaction conditions. Optimization study showed that, K2S2O8 is the best oxidant for the reaction and the mechanistic study proved the radical pathway for this transformation. It was found that the substrates with electron donating or electron withdrawing groups could react smoothly to afford the desired products.
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•Cross-dehydrogenative coupling of pyridine N-oxides with cyclic ethers is carried out using CuO as the catalyst.•This procedure provides a chemo- and regioselective synthetic route to 2-alkylpyridine N-oxides.•Under the oxidative conditions, this Cu-catalyzed reaction proceeds well with fair-to-good yields for most products.