نتایج جستجو برای: hydroxyl group
تعداد نتایج: 995287 فیلتر نتایج به سال:
The title compound, C(18)H(12)N(2)O, crystallizes in a phenol-imine tautomeric form with a Z conformation for the imine functionality. The dihedral angle between the aromatic rings is 8.98 (9)°. A strong intra-molecular O-H⋯N hydrogen-bond inter-action between the hydroxyl group and imine N atom occurs.
With the goal of library generation using a polycyclic derivative 5 having an enamide functional group, a simple and practical, enantioselective synthesis of tetrahydroquinoline derivative 2 was achieved. The phenolic hydroxyl group in compound 2 was utilized as an anchoring site for solid-phase synthesis. The ring closing metathesis approach yielded the desired polycyclic product 5 on solid ph...
The relative populations of two amino-hydroxy conformers of cytosine, differing in rotation of the OH group by approximately 180 degrees , were selectively and repeatedly manipulated with narrowband, near-infrared laser light. For cytosine monomers isolated in a low-temperature Ar matrix, laser irradiations at 7013 cm(-1) and at 7034 cm(-1) were found to induce effective transformations of the ...
Hexakis(4-methoxyphenyl)benzene (HPB-OMe(1)) and hexakis(2,6-dimethyl-4-methoxyphenyl)benzene (HPB-OMe(2)) were synthesized via organometallic complex catalysis. The treatment of HPB-OMe(1) with FeCl3 caused cyclodehydrogenation at two positions to yield an oligophenylene with an indeno[1,2-b]fluorene structure (IF-OMe). Deprotection of the methoxy groups of these compounds was conducted by tre...
The plant phenolic compounds such as flavonoids, tannins and phenolic acids appeared to be strong antiradical and antioxidant compounds. The number of hydroxy groups and the presence of a 2,3-double bond and orthodiphenolic structure enhance antiradical and antioxidative activity of flavonoids. The glycosylation, blocking the 3-OH group in C-ring, lack of a hydroxy group or the presence of only...
The crystal structure of the title polymeric complex, [CuCl(2)(C(3)H(6)N(4)O)(2)](n), was obtained by the Rietveld refinement from laboratory X-ray powder diffraction data collected at room temperature. The unique Cu(II) ion lies on an inversion center and is in a slightly distorted octa-hedral coordination environment. In the hydroxy-ethyl group, all H atoms, the O atom and its attached C atom...
The effect of water on the stability and vibrational states of a hydroxy-isoprene adduct is probed through the introduction of 1-15 water molecules. It is found that when a static nuclear harmonic approximation is invoked there is a substantial red-shift of the alcohol O-H stretch (of the order of 800 cm(-1)) as a result of introduction of water. When potential energy surface sampling and assoc...
Synthesis of cyclopenta[b]pyrane derivatives via Achmatowicz oxidative cyclization of furanols followed by intramolecular Knoevenagel condensation of the β-ketoester arm is examined. The extent of diastereoselectivity was dependent on the nature of the chiral atom within the tethering carbon of the pyrenone ring. In some cases, this process proceeds with a high degree of stereoselectivity after...
We previously used in vitro selection to identify several classes of deoxyribozymes that mediate RNA ligation by attack of a hydroxyl group at a 5'-triphosphate. In these reactions, the nucleophilic hydroxyl group is located at an internal 2'-position of an RNA substrate, leading to 2',5'-branched RNA. To obtain deoxyribozymes that instead create linear 3'-5'-linked (native) RNA, here we strate...
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