Chemische Untersuchung der Königskerzenbl\ten (Flores verbasci)

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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     

The preparation and thermal dimerization study of a trifluorovinyl-containing imide. Application to the synthesis of a trifluorovinyl-containing polyimide precursor

Elaboration of 2-fluoro-α,β,β-trifluorostyrene 7, prepared by the palladium catalyzed coupling reaction of l-fluoro-2-iodobenzene with a trifluorovinylzinc reagent, yielded the trifluorovinyl-containing imide 1. Thermal dimerization of 1 at 140-160°C leads predominately to the corresponding E-cyclobutane 12, whose structure was established by x-ray crystallography. Similar methodology was utilized to prepare 2,2-bis{4-[4-amino-2-(l,2,2-trifluoroethenyl)phenoxy]phenyl)hexafluoropropane 19 , a precursor to the trifluorovinyl-containing polyimide 18 .