Regioselectivity in the amination of azines. Reaction of 1,10-phenanthroline derivatives with O-mesitylsulfonylhydroxylamine

Regioselectivity in the amination of azines: Reaction of pyrazine derivatives with O-mesitylenesulfonylhydroxylamine

“…Such salts having several nitrogen atoms in the ring are also promising as energetic materials [18][19][20]. Salts of N-amino cations are usually prepared by direct amination of nitrogen-containing heterocycles with various aminating agents; among the latter, O-mesitylenesulfonylhydroxylamine (MSH) is used most widely [11][12][13].If a heteroaromatic compounds contains nitrogen atoms with different environments, amination regioselectivity problem arises [13,21]. We previously studied reactions of 3-bromo-, 4-methyl-, and 5-nitro-1,10-phenanthrolines with MSH and found that the ratio of the resulting isomeric amino cations is determined by their relative stability [21].…”

“…If a heteroaromatic compounds contains nitrogen atoms with different environments, amination regioselectivity problem arises [13,21]. We previously studied reactions of 3-bromo-, 4-methyl-, and 5-nitro-1,10-phenanthrolines with MSH and found that the ratio of the resulting isomeric amino cations is determined by their relative stability [21].…”

Regioselectivity in the amination of methylsulfanyl-substituted azines with O-mesitylenesulfonylhydroxylamine

“…Direct amination of nitrogen-containing heteroaromatic compounds with H 2 NX reagents generally occurs at the nitrogen atom [1][2][3][4][5][6]. If several nonequivalent nitrogen atoms are present, the site of addition of amino group depends on the nature of substituents [1,[4][5][6].…”

“…If several nonequivalent nitrogen atoms are present, the site of addition of amino group depends on the nature of substituents [1,[4][5][6]. O-Mesitylenesulfonylhydroxylamine MesSO 3 NH 2 is one of the most widely used reagents for the amination of nitrogen-containing heterocycles [1][2][3][4][5][6]. Its reactions with alkylsulfanyl-substituted pyridines give the corresponding aminosulfonium salts, i.e., the amination involves sulfur rather than nitrogen atom in the substrate [7,8].…”

“…Calculated (DFT/3Z) total energies of transition states (E tot , a.u. ), energy barriers (E a , kJ/mol), and rate constant ratios for the amination of azines I, IIa, and IIb and 2-methylsulfanylpyridine at the sulfur and nitrogen atoms nor intermolecular transfer of the amino group even under fairly severe conditions [5]. Therefore, intra-or intermolecular transfer of the amino group cannot be regarded as complicating factor while studying regioselectivity in the amination of azines.…”