Syntheses of new conformationally constrained S‐[2‐[(1‐iminoethyl)amino] ethyl]homocysteine derivatives as potential nitric oxide synthase inhibitors

The efficient syntheses of two new types of conformationally constrained S‐[2‐[(1‐iminoethyl)amino]ethyl]homocysteine derivatives, 1‐amino‐3‐[2[(1‐iminoethyl)amino]ethylthio]cyclobutane carboxylic Acid ( 5 ) and (4S)‐4‐[[2‐[(1‐Iminoethyl)amino]ethyl]thio]‐L‐proline ( 6 ), are reported. These molecules represent the first attempts to probe conformational constraint near the α‐amino acid moiety of known homocysteine‐based inhibitors of nitric oxide synthase. Targets 5 and 6 were evaluated as potential inhibitors of the three human isoforms of nitric oxide synthase. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:77–83, 2002; DOI 10.1002/hc.1109     

Copper (I)-BOX Catalyzed Asymmetric 3-Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines**

An asymmetric 3-component reaction between EthynylBenziodoXoles (EBXs), 2,2,2-trifluorodiazoethane and nucleophiles catalyzed by a Cu^I-BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and anilines, which are valuable building blocks in synthetic and medicinal chemistry. The reaction proceeds with high enantioselectivity and yield with different nucleophiles such as primary, secondary and tertiary alcohols, as well as both electron-rich and electron-poor anilines. Aryl-, alkyl- and silyl-substituted alkynes can be successfully introduced as electrophiles. In case of chiral substrates, high catalyst control was observed, leading to good diastereoselectivity.     

Growth and characterization of pure and Hg2+ doped thiosemicarbazide cadmium chloride crystals

Semiorganic single crystals of thiosemicarbazide cadmium chloride (TSCCC) and mercury ions doped thiosemicarbazide cadmium chloride were synthesized by slow solvent evaporation technique. The grown crystals were subjected to powder X‐ray analysis and both the crystals were found to crystallize in the monoclinic system. EDAX analysis was carried out for chemical analysis of the grown crystals. The UV‐Vis‐NIR spectrum shows that both the materials have wide transparency window in the visible and near IR region. The dielectric studies were carried out to estimate the dielectric constant and dielectric loss with respect to frequency for both the crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)