Spiro ring systems have two or more rings linked by one common atom. Several different methods are used to name such systems. Rules A-41, A-43, B-b and B-12 (Nomenclature of Organic Chemistry, 1979) describe the basics of how to name these compounds. The alternative methods in rules A-42 and B-i 1 are abandoned. This document describes the nomenclature in greater detail and extends it to cover ...

We have revisited the photochromic spiro-dihydroindolizine/betaine (DHI/B) system applying state-of-the-art density functional theory (DFT) calculations in combination with stationary and time-resolved absorption measurements. DHI/B-systems are becoming increasingly important as potential molecular machines, molecular switches, and photoswitchable electron-acceptors. The knowledge of the exact ...

The crystal structure of the title compound, C(30)H(38)N(2)O(5)Si, has been investigated to establish the relative stereochemistry at the spiro ring junction and the two anomeric centres. Each of the O atoms in the tetra-hydro-pyran rings adopts an axial position on the neighbouring ring. This bis--diaxial conformation is adopted, thus gaining maximum stablization from the anomeric effect. The ...

The first total synthesis of the oxindole alkaloid gelsedine (1) starting from (S)-malic acid is described. The key step is a novel iodide-promoted intramolecular reaction of an allene with an N-acyliminium ion intermediate which provided in a single step the bicyclic vinyl iodide 11. Other important steps are the highly stereoselective Pd-catalyzed Heck cyclization of N-methylanilide 23a which...

The synthesis and evaluation of the anticancer activity of 3'-aryl-5'-arylidene-spiro[3H-indole-3,2'-thiazolidine]-2,4'(1H)-diones and spiro[3H-indole-3,2'-thi-azolidine]-2,4'(1H)-dione-3'-alkanoic acid esters were described. The structure of the compounds was determined by (1)H and (13)C NMR and their in vitro anticancer activity was tested in the National Cancer Institute. Among the tested co...

2,2',7,7'-Tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD), the prevalent organic hole transport material used in solid-state dye-sensitized solar cells and perovskite-absorber solar cells, relies on an uncontrolled oxidative process to reach appreciable conductivity. This work presents the use of a dicationic salt of spiro-OMeTAD, named spiro(TFSI)2, as a facile means ...

Various analogues of the anti-HIV-1 agent TSAO-T, [1-[2',5'-bis-O-(tert-butyldimethylsilyl)-beta-D-ribofuranosyl]thymine]-3'-spiro-5"-(4"-amino-1",2"-oxathiole-2",2"-dioxide) have been synthesized in which the 5'-TBDMS group has been replaced by alkyl-, alkenyl- or aromatic ether groups, substituted amines, carbamoyl or (thio)acyl groups. The compounds synthesized were evaluated for their inhib...

Standard acetonitrile/tetraalkylammonium-tetrafluoroborate-based electrochemical capacitor electrolytes were modified with both fluorinated additives (including analogs of ethylmethyl carbonate and diethyl carbonate, lithium difluoro(oxalato)borate, tris(2,2,2-trifluoroethyl) phosphite) spiro(1,1?)-bipyrrolidinium tetrafluoroborate salt, to improve stability at higher voltages (>2.7 V). Compoun...

Metal-halide perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies in recent years, and spiro-OMeTAD plays a significant role as hole transport material PSCs with record efficiencies. However, further studies systematic experimental procedures on doped are required to enable reliable process for potential commercialization. In particular, the effect of prolonged o...