نتایج جستجو برای: spiro

تعداد نتایج: 2198  

2013
Muhammet Işıklan Ömer Sonkaya Tuncer Hökelek

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...

Journal: :The Journal of antibiotics 1987
R Misra R C Pandey B D Hilton P P Roller J V Silverton

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...

2012
Ilia A. Guzei Lara C. Spencer Eric Codner Joshua M. Boehm

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 ...

Journal: :Molecules 2013
Harold D Cooper Dennis L Wright

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 ...

2013
Arianna Marchioro Jan C. Brauer Joël Teuscher Michael Grätzel Natalie Banerji Carlos Silva

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...

Journal: :Molecules 2017
Ádám A Kelemen Grzegorz Satala Andrzej J Bojarski György M Keserű

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...

Journal: :The Journal of organic chemistry 2005
Tien Q Pham Stephen G Pyne Brian W Skelton Allan H White

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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