نتایج جستجو برای: p cymene
تعداد نتایج: 1269825 فیلتر نتایج به سال:
We present nucleophilic aromatic substitution of unsubstituted aryl chlorides via a mechanism that is catalytic in [CpRu(p-cymene)]PF6 and involves a Ru(η(6)-arylchloride) intermediate. From the spectroscopic evidence we infer that arene exchange is the rate limiting step in this process and develop several new Ru(ii) complexes that lower the activation barrier to arene exchange.
Satureja wiedemanniana (Lallem.) Velen (Lamiaceae) is an endemic species of Turkey. Aerial parts of the plant collected from eleven different localities in Turkey were subjected to hydrodistillation to yield essential oils which were analysed by a GC/MS system. Carvacrol, thymol, p-cymene and gamma-terpinene were found as the main constituents. Antibacterial evaluation of the oils was also carr...
Ruthenium/Me-BIPAM-catalyzed asymmetric addition of arylboronic acids to methyl 2-formylbenzoates afforded chiral 3-aryl-isobenzofuranones. [RuCl2(p-cymene)]2/Me-BIPAM and RuCl2(PPh3)3/Me-BIPAM catalyst systems tolerate a variety of functional groups and give high yields with high enantioselectivities.
A fast and simple method based on ultrasound-assisted emulsification microextraction (USAEME) was developed for the analysis of volatile compounds in wines. full factorial 24 screening design built to investigate main factors affecting extraction components, namely volume solvent, sonication time, salt content, pH. Then, with significant effects were optimized using an I-optimal design. The opt...
The chemical composition of the essential oils from aerial parts of Pectis apodocephala and Pectis oligocephala were analyzed by GC-MS. The essential oils of these species were predominantly constituted by monoterpenes. Geranial (42.9-44.5%), neral (32.2-34.2%) and alpha-pinene (10.7-11.4%) were the main constituents in the oil of P. apodocephala, while p-cymene (50.3-70.9%) and thymol (24.4-44...
The activation of the C-H bond of 1-phenylpyrazole (2) and 2-phenyl-2-oxazoline (3) by [Ru(OAc)2(p-cymene)] is an autocatalytic process catalyzed by the co-product HOAc. The reactions are indeed faster in the presence of acetic acid and water but slower in the presence of a base K2CO3. A reactivity order is established in the absence of additives: 2-phenylpyridine>2-phenyl-2-oxazoline>1-phenylp...
Abstract Ruthenium(II)-catalyzed enantioselective C–H functionalization reactions of sulfoximines with sulfoxonium ylides are described. The combination [RuCl2(p-cymene)]2 and a pseudo-C 2-symmetric binaphthyl monocarboxylic acid furnished the S-chiral products in 76:24 to 92:8 er.
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