Selective synthesis of β-nitrated N-heterocycles and N-nitroso-2-alkoxyamine aldehydes from inactivated cyclic amines promoted by tBuONO and oxoammonium salt.

A convenient synthesis of β-nitrated tetrahydropyridines has been successfully realized via dehydrogenative β-C-H nitrification of N-arylpiperidines promoted by tBuONO and the oxoammonium salt in THF. In addition, changing the solvent to an acetone/water mixture resulted in selective cleavage and tunable functionalization of the inert C-N bonds in cyclic amines to afford N-nitroso chain 2-alkoxyamine aldehydes. Notably, the application of N-nitroso-2-alkoxyamine aldehydes was showcased by their efficient transformation into 4-substituted 1,2-diazepines featuring a facile construction of a seven-membered ring.