One-step Amination by Parent Nitrenium Ion and Alkylnitrenium Ion

1-氨基吡啶盐和S-氨基磺酸盐类及其在芳烃-三氟乙酸中的衍生物光解生成母体离子、烷基、二烷基和脂环镍离子。光解通过单重态镍离子生成芳香族N-取代产物，通过三重态镍离子生成吸氢产物。其机理由Rho-2.1对Hammett图提出，排除了通过氨基或氨离子的机理，以及重原子或氧分子的作用。改变反应物盐阳离子和阴离子部分的反应活性的结果表明，硝离子既与吡啶或硫化物杂原子的非共享电子对相互作用，又与Gegen阴离子相互作用。因此，单重态氮离子通过这种相互作用而稳定。通过与18-冠-6的相互作用，也稳定了单线态镍离子；在冠醚的存在下，硝离子的N-取代产率增加。硝离子对苯甲醚具有较好的邻位攻击性，很好地支持了硝离子与苯甲醚中氧原子的相互作用。重原子、溶剂和氧分子促进了单重态向三重态的S-T转化。单重态离子越稳定，对S-T转换的促进作用就越明显。在甲苯或均三甲苯的存在下，具有比烷基或母体镍离子更低的单重态和三重态能隙的二烷基或脂环族氮离子在甲苯或均三甲苯的存在下发生快速的S-T转换，这是由于单态和三态之间的快速平衡。另一方面，具有Gegen阴离子i^-的三态母体离子可以通过氮杂环丙烷中间体的扩环反应生成新的化合物1H-和9H-L苯并氮卓或9H-和11H-二苯并[d，f]氮杂环。

Parent, alkyl, dialkyl, and alicyclic nitrenium ions were generated from photolyses of 1-aminopyridinium and S-aminosulphonium salts and the derivatives in arene-trifluoroacetic acid. The photolyses gave aromatic N-substitution pro- ducts via the singlet nitrenium ions and hydrogen abstraction products via the triplet nitrenium ions.The mechanism was suggested by rho -2.1 for Hammett plot, an exclusion of a mechanism through an amino radical or aminium ion, and an effect of heavy atom or oxygen molecule. The result altering the reactivity upon the change of cationic and anionic portions of the reactant salt shows that the nitrenium ion interacts with both the unshared electron pair of the heteroatom of pyridine or sulphide and the Gegen anion. Thus the singlet nitrenium ion is stabilised by this interaction. The singlet nitrenium ion is also stabilised by interaction with 18-crown-6; the yield of N-substitution by the nitrenium ion was increased in the presence of the crown ether. The preferable ortho-attack of the nitrenium ion on anisole well supports the interaction between the nitrenium ion and the oxygen atom of anisole.The S-T conversion of the singlet into the triplet nitrenium ion is promoted by heavy atom solvent and oxygen molecule. The more stabilised singlet nitrenium ions can undergo the more predominant promotion of the S-T conversion. The di- alkyl or alicyclic nitrenium ion having a lower singlet-triplet energy gap than the alkyl or parent nitrenium ion undergoes a fast S-T conversion in the presence of a good hydrogenatom donor such as toluene or mesitylene due to a fast equilibrium between the singlet and triplet states.On the other hand, the triplet parent nitrenium ion with the.Gegen anion I^- is allowed to react with naphthalene or phenanthrene to yield novel compounds, 1H- and 9H-l-benzazepines or 9H- and 11H-dibenzo[d,f]azepines, via the ring- expansion of aziridine intermediates.