40648-13-3Relevant academic research and scientific papers
Copper(II) Complexes with Bulky N-Substituted Diethanolamines: High-Field Electron Paramagnetic Resonance, Magnetic, and Catalytic Studies in Oxidative Cyclohexane Amidation
Nesterova, Oksana V.,Nesterov, Dmytro S.,Jezierska, Julia,Pombeiro, Armando J. L.,Ozarowski, Andrew
, p. 12384 - 12397 (2018/09/25)
The novel coordination compounds [Cu2(HtBuDea)2(OAc)2] (1) and [Cu2(HnBuDea)2Cl2]·nH2O (2) have been prepared through the reaction of the respective copper(II) salts with N-tert-butyldiethanolamine (H2tBuDea, for 1) or N-butyldiethanolamine (H2nBuDea, for 2) in methanol solution. Crystallographic analysis reveals that, in spite of the common binuclear {Cu2(μ-O)2} core, the supramolecular structures of the complexes are drastically different. In 1 binuclear molecules are linked together by H-bonds into 1D chains, while in 2 the neighboring pairs of binuclear molecules are H-bonded, forming tetranuclear aggregates. Variable-temperature (1.8-300 K) magnetic susceptibility measurements of 1 and 2 show a dominant antiferromagnetic behavior. Both complexes are also studied by HF-EPR spectroscopy. While the interaction between Cu(II) centers in 1 can be described by a single coupling constant J = 130.1(3) cm-1 (using H = JS1S2), the crystallographically different {Cu2(μ-O)2} pairs in 2 are expected exchange from ferro- to antiferromagnetic behavior (with J ranging from -32 to 110 cm-1, according to DFT calculations). Complexes 1 and 2 act as catalysts in the amidation of cyclohexane with benzamide, employing tBuOOtBu as oxidant. The maximum achieved conversion of benzamide (20%, after 24 h reaction time) was observed in the 1/tBuOOtBu system. In the cases of tBuOO(O)CPh or tBuOOH oxidants, no significant amidation product was observed, while for tBuOO(O)CPh, the oxidative dehydrogenation of cyclohexane occurred, giving cyclohexene, to afford the allylic ester (cyclohex-2-en-1-yl benzoate) as the main reaction product.
Oxidation of aliphatic and aromatic C[sbnd]H bonds by t-BuOOH catalyzed by μ-nitrido diiron phthalocyanine
Kudrik, Evgeny V.,Sorokin, Alexander B.
, p. 499 - 505 (2016/12/16)
Low temperature selective transformation of alkanes to useful products continues to be an important challenge in chemistry and industry. μ-Nitrido diiron phthalocyanines in combination with H2O2 have been recently identified as powerful oxidation catalysts for these challenging reactions due to the formation of ultra-high valent diiron oxo species PcFe(IV)μNFe(IV)[dbnd]O(Pc+[rad]). This very strong two-electron oxidizing species is generated from peroxo complex PcFe(IV)μNFe(III)[sbnd]O[sbnd]O[sbnd]R(Pc) (R[dbnd]H in the case of H2O2) via heterolytic O[sbnd]O bond cleavage. Therein we show that the evolution of the peroxo diiron complex depends on the peroxide structure. Using tBuOOH we have demonstrated the formation of an one-electron oxidizing PcFe(IV)μNFe(IV)[dbnd]O(Pc) and tBuO[rad] radical via homolytic O[sbnd]O cleavage of the peroxocomplex. The reactivity of the μ-nitrido diiron tetra-t-butylphthalocyanine ? tBuOOH catalytic system was investigated in the oxidation of different C[sbnd]H bonds in alkanes, olefins, aromatic and alkylaromatic compounds. The main products of cyclohexane oxidation were cyclohexanone and cyclohexanol whereas bicyclohexyl was formed in minor amounts even in the presence of O2 and tBuOOH. Under optimal conditions, the turnover numbers of almost 5300 have been achieved.
Selenium Dioxide Oxidation of Endocyclic Olefins. Evidence for a Dissociation-Recombination Pathway
Warpehoski, M. A.,Chabaud, B.,Sharpless, K. B.
, p. 2897 - 2900 (2007/10/02)
The selenium-catalyzed oxidation of some simple alicyclic olefins with tert-butyl hydroperoxide produced, in addition to the expected allylic alcohols, allylic tert-butyl peroxides and allylic tert-butyl ethers.Unlike the peroxides, the ether products were not inhibited by hydroquinone, and their relative amounts increased with decreasing ring size.Analogous products were detected in minor amounts in the selenium dioxide-tert-butyl hydroperoxide oxidation of β-pinene, with isomer distribution suggestive of a symmetrical intermediate.It is proposed that the etherproducts arise via a dissociation-recombination pathway competitive with the sigmatropic shift leading to the alcohol.Examination of the literature suggests that such a pathway may also be significant in selenium dioxide oxidations of small ring compounds in which ring oxidation occurs and may lead to unexpected products in which the double bond has moved from its original position.
