نتایج جستجو برای: pyran annulated hetrocyclic systems
تعداد نتایج: 1185076 فیلتر نتایج به سال:
Tetrathiafulvalenes (TTF)-annulated [28]hexaphyrin affords an electron rich flexible π-conjugated system whose limiting conformations can be controlled through choice of solvents. The conformation-dependent intramolecular charge transfer character, as well as electron reserve capability of the hexakis-TTF annulated hexaphyrin, was analyzed.
In the title compound, C(9)H(8)O(2), a benzo-annulated heterocyclic ketone, the non-aromatic six-membered ring adopts an E(2) conformation. In the crystal, C-H⋯O contacts connect the mol-ecules into double sheets perpendicular to the crystallographic a axis. The centroid-centroid distance for two π-systems is 3.7699 (6) Å.
The degree of activation of peritoneal macrophages elicited by pyran copolymer (MVE-2) was studied in C57BL/6J mice. When cytotoxicity was examined under endotoxin-free culture conditions, the pyran-elicited macrophages could not complete cytolysis of tumor target cells. The macrophages, however, completed cytolysis when pulsed with endotoxin. These results were obtained when either the interva...
Pyran covalently linked to cyanogen bromide-activated Sepharose has been shown to be an effective affinity matrix for several viral DNA polymerases. Differential salt elution of viral compared with cellular polymerases, as well as substrate elution, suggests the affinity nature for the matrix. Unlike some other affinity systems described, pyran-Sepharose is totally resistant to nuclease digesti...
The desymmetrisation of 1,4-difuran-2-ylbutane-1,4-diol by Sharpless asymmetric oxidation gave the corresponding desymmetrised product in > 96% ee. However, the product existed as a mixture of two interconverting isomers, both of which were mixtures of anomers. The product could be trapped in high yield with a range of reagents to give stable adducts with embedded pyran-3-one, 1,6-dioxaspiro[4....
An intramolecular dehydrogenative C-H activation enabled an efficient synthesis of an uracil-annulated β-carbolinone ring system. The reaction is simple, efficient and high yielding (85-92%).
The intermolecular [2+2] cycloaddition of allenol esters, which were in situ generated by Pt-catalyzed 1,3-acyloxy migration of propargylic esters, with C60 proceeded regio- and stereo-selectively to give a novel class of alkylidenecyclobutane-annulated fullerenes. The cyclobutane-annulated fullerene derivatives have high-lying LUMO levels, which gave a high open-circuit voltage in organic sola...
The N-heterocyclic carbene catalyzed annulation of benzofuran-2,3-diones and enals via homoenolate intermediates is described. The reaction provided a direct and efficient method for the synthesis of spiro-bis-lactones. The ketone-carbonyl group annulated products and the ester-carbonyl group annulated products can be obtained as major products with good yields by convenient catalyst regulation...
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