668994-46-5Relevant articles and documents
A versatile tripodal Cu(I) reagent for C-N bond construction via nitrene-transfer chemistry: Catalytic perspectives and mechanistic insights on C-H aminations/amidinations and olefin aziridinations
Bagchi, Vivek,Paraskevopoulou, Patrina,Das, Purak,Chi, Lingyu,Wang, Qiuwen,Choudhury, Amitava,Mathieson, Jennifer S.,Cronin, Leroy,Pardue, Daniel B.,Cundari, Thomas R.,Mitrikas, George,Sanakis, Yiannis,Stavropoulos, Pericles
supporting information, p. 11362 - 11381 (2014/09/17)
A CuI catalyst (1), supported by a framework of strongly basic guanidinato moieties, mediates nitrene-transfer from PhI=NR sources to a wide variety of aliphatic hydrocarbons (C-H amination or amidination in the presence of nitriles) and olefins (aziridination). Product profiles are consistent with a stepwise rather than concerted C-N bond formation. Mechanistic investigations with the aid of Hammett plots, kinetic isotope effects, labeled stereochemical probes, and radical traps and clocks allow us to conclude that carboradical intermediates play a major role and are generated by hydrogen-atom abstraction from substrate C-H bonds or initial nitrene-addition to one of the olefinic carbons. Subsequent processes include solvent-caged radical recombination to afford the major amination and aziridination products but also one-electron oxidation of diffusively free carboradicals to generate amidination products due to carbocation participation. Analyses of metal- and ligand-centered events by variable temperature electrospray mass spectrometry, cyclic voltammetry, and electron paramagnetic resonance spectroscopy, coupled with computational studies, indicate that an active, but still elusive, copper-nitrene (S = 1) intermediate initially abstracts a hydrogen atom from, or adds nitrene to, C-H and C=C bonds, respectively, followed by a spin flip and radical rebound to afford intra- and intermolecular C-N containing products.
Half-sandwich scorpionates as nitrene transfer catalysts
Liang, Shengwen,Jensen, Michael P.
, p. 8055 - 8058 (2013/02/22)
Scorpionate complexes of the middle to late 3d transition metals [(L)M(NCMe)3](BF4)n (M = Mn, Fe, Co, Ni: 1 M, L = tris(3,5-dimethylpyrazol-1-yl)methane, TpmMe,Me, n = 2; 2M, L = tris(3-phenylpyrazol-1-yl)methane, TpmPh, n = 2; 3M except 3Mn, L = hydrotris(3,5-dimethylpyrazol-1-yl) borate, [TpMe,Me]-, n = 1; 4M, L = hydrotris(3-phenyl-5-methylpyrazol-1-yl)borate, [TpPh,Me] -, n = 1) were examined as catalysts for styrene aziridination and THF amination using phenyl-N-tosyliodinane as a nitrene donor. [(Tpm Me,Me)Fe(NCMe)3](BF4)2 (1 Fe) was identified as the most active catalyst, giving nearly quantitative nitrene transfer yields at 5 mol % loadings. The reactivity of 1Fe with a wider range of organic substrates was also explored, and a striking observation was strong selectivity for aromatic rather than benzylic amination for alkylaromatic substrates.
Copper(ii) complexes incorporating poly/perfluorinated alkoxyaluminate-type weakly coordinating anions: Syntheses, characterization and catalytic application in stereoselective olefin aziridination
Li, Yang,He, Jiayue,Khankhoje, Vineeta,Herdtweck, Eberhardt,Koehler, Klaus,Storcheva, Oksana,Cokoja, Mirza,Kuehn, Fritz E.
supporting information; experimental part, p. 5746 - 5754 (2011/08/02)
The synthesis and characterization of a series of cationic copper(ii) complexes of the type [Cu(NCR)6][Al(OC(CF3) 2R′)4]2 (R = CH3, Ph; R′ = CF3, Ph, PhCH3), incorpora