16166-61-3Relevant articles and documents
Highly enantioselective copper-bisoxazoline-catalyzed allylic oxidation of cyclic olefins with tert-butyl p-nitroperbenzoate
Andrus, Merritt B.,Zhou, Ziniu
, p. 8806 - 8807 (2002)
Catalytic asymmetric allylic oxidation of cyclic olefins ocurrs for the first time in very high (94-99% ee) enantioselectivity using copper(I) complexes of malonyl derived bisoxazolines and tert-butyl p-nitroperbenzoate giving allyl benzoates in moderate
Immobilization of (l)-valine and (l)-valinol on SBA-15 nanoporous silica and their application as chiral heterogeneous ligands in the Cu-catalyzed asymmetric allylic oxidation of alkenes
Ashouri, Akram,Mahramasrar, Mahsa,Majidian, Shiva,Rashid, Hersh I,Samadi, Saadi
, p. 17630 - 17641 (2021/10/04)
SBA-15 nanoporous silica was synthesized by hydrothermal method using P123 surfactant and tetraethoxyortosilicate in acidic condition and then functionalized by 3-chloropropyltrimethoxysilane. Next, by immobilization of chiral amino acid (S)-2-amino-3-methyl butanoic acid (l-valine) and chiral amino alcohol (S)-2-amino-3-methylbutane-1-ol (l-valinol), preparedviathe reduction ofl-valine by NaBH4/I2in THF, on functionalized-SBA-15, chiral heterogeneous ligands AL*-i-Pr-SBA-15 and AA*-i-Pr-SBA-15 were prepared and characterized by FT-IR, XRD, TGA, EDX, SEM, BET-BJH techniques. The asymmetric allylic oxidation of alkenes was done using copper-complexes of these ligands and the as-synthesized peresters. The reactions were optimized by varying various parameters such as temperature, solvent, amount of chiral heterogeneous ligand, as well as the type and amount of copper salt. Under optimized conditions, 6 mg of AL*-i-Pr-SBA-15 and 3.2 mol% of Cu(CH3CN)4PF6in acetonitrile at 50 °C, the chiral allylic ester was obtained with 80% yield and 39% enantiomeric excess in 24 h. The recyclability of the chiral heterogeneous catalysts was also evaluated without significant reduction in the reaction results up to three runs.
A Woven Supramolecular Metal-Organic Framework Comprising a Ruthenium Bis(terpyridine) Complex and Cucurbit[8]uril: Enhanced Catalytic Activity toward Alcohol Oxidation
Li, Zhan-Ting,Liu, Yi,Wang, Hui,Wang, Ze-Kun,Xu, Zi-Yue,Zhang, Dan-Wei,Zhang, Yun-Chang
, p. 1498 - 1503 (2020/08/05)
The self-assembly of a diamondoid woven supramolecular metal–organic framework wSMOF-1 has been achieved from intertwined [Ru(tpy)2]2+ (tpy=2,2′,6′,2′′-terpyridine) complex M1 and cucurbit[8]uril (CB[8]) in water, where the intermolecular dimers formed by the appended aromatic arms of M1 are encapsulated in CB[8]. wSMOF-1 exhibits ordered pore periodicity in both water and the solid state, as confirmed by a combination of 1H NMR spectroscopy, UV-vis absorption, isothermal titration calorimetry, dynamic light scattering, small angle X-ray scattering and selected area electron diffraction experiments. The woven framework has a pore aperture of 2.1 nm, which allows for the free access of both secondary and primary alcohols and tert-butyl hydroperoxide (TBHP). Compared with the control molecule [Ru(tpy)2]Cl2, the [Ru(tpy)2]2+ unit of wSMOF-1 exhibits a remarkably higher heterogeneous catalysis activity for the oxidation of alcohols by TBHP in n-hexane. For the oxidation of 1-phenylethan-1-ol, the yield of acetophenone was increased from 10 percent to 95 percent.
Designing chiral amido-oxazolines as new chelating ligands devoted to direct Cu-catalyzed oxidation of allylic C–H bonds in cyclic olefins
Samadi, Saadi,Jadidi, Khosrow,Samadi, Mojgan,Ashouri, Akram,Notash, Behrouz
, p. 862 - 867 (2019/01/08)
A new type of amido-oxazoline ligands was conveniently synthesized from inexpensive and commercially available materials in high yields and enantiomeric excesses. The corresponding chiral copper complexes with this class of ligands [C2 symmetric S,S-bis(amido-oxazoline-Cu(II) complex] were synthesized accordingly. The ORTEP diagram of ligand 6a and complex 6a-copper were compared and characterization of the complex confirmed the involvement of both dentate parts of the ligands, the oxygen and nitrogen atoms, in complexation with copper. The utilization of this amido-oxazoline ligands in the copper-catalyzed enantioselective esterification of allylic C–H bonds of cyclic olefins with tert-butyl-4-nitrobenzoperoxoate resulted in the highest activities, yields (up to 95%) and enantioselectivities (up to 96%) in the presence of HZSM-5 zeolite. These new findings highlight the protocol as one of the most attractive and useful methods for the oxidation of the asymmetric allylic C–H bond of cycloalkenes compared to other methodologies reported in the literature.