Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

• David Porter,
• Belinda M.-L. Poon and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

• -chlorophenyl)hydroxylamine using a molybdenum complex [32], a process that was made catalytic by adding excess N-phenylhydroxylamine [33]. The combination of iron(II) phthalocyanines [34][35] or iron(II)/iron(III) chloride [36][37][38] and N-phenylhydroxylamine effect allylic amination reactions that are

• believed to follow a nitroso–ene mechanism. Similar reactions have been reported using copper salts and N-phenylhydroxylamine [39] or N-Boc-hydroxylamine [40][41], presumably via oxidation of the hydroxylamine to a nitroso species which then undergoes the nitroso–ene reaction. Stemming from our interest in

• is a trickier proposition [14], although this has been demonstrated in an intramolecular context [22]. Mechanistic studies Previous studies of iron-promoted allylic amination reactions with N-phenylhydroxylamine, and copper-catalysed reactions with N-Boc-hydroxylamine (8) return regio- and

An aniline dication-like transition state in the Bamberger rearrangement

• Shinichi Yamabe,
• Guixiang Zeng,
• Wei Guan and
• Shigeyoshi Sakaki

Beilstein J. Org. Chem. 2013, 9, 1073–1082, doi:10.3762/bjoc.9.119

• Shinichi Yamabe Guixiang Zeng Wei Guan Shigeyoshi Sakaki Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103, JAPAN. Phone: +81-075-711-7907 10.3762/bjoc.9.119 Abstract A Bamberger rearrangement of N-phenylhydroxylamine, Ph–N(OH)H, to

• activation energy similar to the experimental one was obtained. A new mechanism of the rearrangement including the aniline dication-like transition state was proposed. Keywords: Bamberger rearrangement; DFT calculations; N-phenylhydroxylamine; proton transfer; reactive intermediates; transition states

• intermolecular nature was also proven by a rearrangement of N-ethyl-N-phenylhydroxylamine, Et–N(OH)–Ph 3, in methanol leading to p-(ethylamino)anisole 4 (Scheme 3) [5]. Through the kinetic measurement, the rearrangement was claimed to occur by an SN1 mechanism [6]. Also, it was reported that the elimination of