نتایج جستجو برای: spiro
تعداد نتایج: 2198 فیلتر نتایج به سال:
In the title spiro-phosphazene derivative, C33H46N9OP3, the phosphazene and six-membered N/O rings are in flattened chair and twisted-boat conformations, respectively. The naphthalene ring system and the pyridine ring are oriented at a dihedral angle of 41.82 (4)°. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules related by translation along the a axis into chains. C-H⋯π inter-acti...
IR, UV-visible spectroscopy, circular dichroism, 1H and 13C NMR studies, high resolution electron impact, field desorption, and fast atom bombardment mass spectral studies are reported for fredericamycin A (NSC-305263), a novel antitumor antibiotic of acid-base indicator type produced by Streptomyces griseus (FCRC-48). The spectral data are correlated with the structure obtained by X-ray crysta...
The title compound, C(28)H(30)N(2), is a symmetrical 2:2 product from the condensation of indole and cyclo-hexa-none. It is the only reported 5,11-dihydro-indolo[3,2-b]carbazole compound in which the spiro atoms are quaternary C atoms. Crystals were grown by vapor diffusion in a three-zone electric furnace. The mol-ecule resides on a crystallographic inversion center. The cyclo-hexyl rings are ...
Phelligridin G is an unusual natural product that contains an embedded spiro-fused furanone core. We have investigated two furan-based synthetic approaches towards the spirocyclic core structure of this natural product from readily available 2-phenylfurans. Although initial studies involving an oxidative cyclization were unsuccessful, we were ultimately able to access this key system through ...
Organic-inorganic hybrid systems based on lead halide compounds have recently encountered considerable success as light absorbers in solid-state solar cells. Herein we show how fundamental mechanistic processes in mesoporous oxide films impregnated with CH3NH3PbI3 can be investigated by time resolved techniques. In particular, charge separation reactions such as electron injection into the tita...
Synthetic derivatives of spiro[pyrrolidinyl-3,3'-oxindole] alkaloids (coerulescine analogues) were investigated as new ligands for aminergic G-protein coupled receptors (GPCRs). The chemical starting point 2'-phenylspiro[indoline-3,3'-pyrrolidin]-2-one scaffold was identified by virtual fragment screening utilizing ligand- and structure based methods. As a part of the hit-to-lead optimization a...
The phosphine-catalyzed [3 + 2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c ...
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