A new approach towards the synthesis of indole derivatives via triflic acid-promoted cycloisomerization with rearrangement of 2-(alkyn-1-yl)phenyl isothiocyanates and 2-(alkyn-1-yl)phenyl isocyanates has been achieved. By this methodology, structurally diverse types of indole derivatives such as thieno- and furo-indoles, spiro-indolethiones, spiro-oxindoles, and 3-alkylidene-oxindoles were synt...

The structural and electronic properties of C24-2nBn Nn and M@ C24-2nBn Nn (M= alkaline and earth alkaline metals; n=3 and 6) molecules are studied using the Density Functional Theory (DFT). It was found that the most interaction is in M@ C24-2nBn Nn complexes (M=Be, Mg; n=3 and 6). The negative nucleus-independent chemical shifts confirm that C24-2nBn Nn (n=3 and 6) cages exhibit aromatic char...

A series of novel 2-alkylidene imidazolines has been synthesized from imidazolium halides and substituted alkyl halides in the presence of base. The resultant exocyclic enediamines have been characterized and their nucleophilicity has been evaluated upon NMR spectroscopic data and substitution reactions.

The synthesis of a monosilylated Grubbs-Hoveyda ruthenium alkylidene complex is described, as well as the preparation and characterization of the corresponding material by sol-gel cogelification with tetraethoxysilane (TEOS) and the assay of this recyclable supported catalyst in ring-closing diene and enyne metathesis reactions under thermal and microwave conditions.

numerous studies yet have been carried out on downscaling of the large-scale climate data usingboth dynamical and statistical methods to investigate the hydrological and meteorological impacts of climatechange on different parts of the world. this study was also conducted to investigate the capability of feedforwardneural network with error back-propagation algorithm to downscale the provincial...

The amide-directed synthesis of five-coordinate osmium alkylidene derivatives from alkynes is reported. These types of complexes, which have been elusive until now because of the tendency of osmium to give hydride alkylidyne species, are prepared by reaction of the dihydride OsH2Cl2(PiPr3)2 (1) with terminal alkynes containing a distal amide group. Complex 1 reacts with N-phenylhex-5-ynamide an...

Atom efficient processes such as the Diels-Alder reaction (DA) and the ring-rearrangement metathesis (RRM) have been used to design new polycycles. In this regard, ruthenium alkylidene catalysts are effective in realizing the RRM of bis-norbornene derivatives prepared by DA reaction and Grignard addition. Here, fused polycycles are assembled which are difficult to produce by conventional synthe...

A thermal [2 + 2] cycloaddition reaction of allene-ynes has been used to transform chiral non-racemic allenyl oxindoles into chiral non-racemic spirooxindoles containing an alkylidene cyclobutene moiety. The enantiomeric excesses were determined by chiral lanthanide shift NMR analysis and the transfer of chiral information from the allene to the spirooxindole was found to be greater than 95%.

A highly regioselective SN2' Mitsunobu reaction between Morita-Baylis-Hillman (MBH) alcohols, azodicarboxylates, and triphenylphosphine is developed, which provides an easy access to α-alkylidene-β-hydrazino acid derivatives in high yields and good stereoselectivity. This reaction represents the first direct transformation of MBH alcohols into hydrazines.

A novel axially chiral spiro-phosphine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of alkylidene azlactones with various allenic esters has been developed, affording the corresponding functionalized spirocyclic products in moderate to excellent yields under mild conditions. These spirocyclic products as masked amino acids can be easily transformed into aspartic ...