Pyrrolopyrimidine nucleosides. XIII. Synthesis and chemical reactivity of certain selenopyrrolo[2,3-d]pyrimidine nucleosides

5-Cyano-7-(β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidin-4-selone ( 1 ) has been prepared via a reaction of the appropriate 4-chloro compound with sodium hydrogen selenide. Alkylation of 2 under basic conditions has provided certain 4-substitutedseleno-5-cyano-7-(β-D-ribofuranosyl)-pyrrolo[2,3-d]pyrimidines. 5-Cyano-4-methylseleno-7-(β-D-ribofuranosyl)pyrrolo[2,3-d]pyrimidine was allowed to react with hydroxylamine and hydrazine. The products obtained and reaction course were compared to those obtained from identical reactions using the corresponding sulfur analog.     

Spatial determination of gold catalyst residue used in the production of ZnO nanowires by SIMS depth profiling analysis

In this paper we demonstrate how secondary ion mass spectrometry (SIMS) can be applied to ZnO nanowire structures for gold catalyst residue determination. Gold plays a significant role in determining the structural properties of such nanowires, with the location of the gold after growth being a strong indicator of the growth mechanism. For the material investigated here, we find that the gold remains at the substrate–nanowire interface. This was not anticipated as the usual growth mechanism associated with catalyst growth is of a vapour–liquid–solid (VLS) type. The results presented here favour a vapour–solid (VS) growth mechanism instead. Copyright © 2007 John Wiley & Sons, Ltd.     

Some reactions of allene and acetylenes with vinylplatinum and methylpalladium complexes

The reactions of cationic vinylplatinum complexes, Pt(R¹CCHR²(PEt₃)₂-(acetone)⁺ PF₆^?, with allene and activated acetylenes yield π-allyl and δ-butadienyl products, respectively. Similar reactions of Pd(CH₃)X(Diphos) (X = Cl, NO₃, solvent, Diphos = 1,2-bis(diphenylphosphino)ethane) with acetylenes are also described. Factors affecting these insertion reactions are discussed.     

A substructure-oriented 13c-nmr chemical shift retrieval system

A computer program that uses on-line generated substructures of organic compounds as input and retrieves the corresponding distributions of ¹³C-n.m.r. chemical shifts is described and discussed. The procedure of creating the substructures and the main features of the retrieval philosophy are outlined. One search is worked out in detail to demonstrate the ability of the system.     

Die Infrarot- und RAMAN-Spektren der Alkalifluorosulfate

For the alkali fluorosulfates MSO₃F infrared spectra (M = Li, Na, K, Rb, Cs) and also RAMAN spectra (M = K, Rb, Cs) have been recorded. The results are discussed to get some information about the lattice structures. The C₃ axis of the anion has several possibilities of orientation in the unit cell for the salts with heavy cations.     

NMR spectroscopy in distinguishing between 3-piperidyl- and 2-pyrrolidylmethyl alcohols,amines, esters,and amides

Nmr analysis was found to be superior to an older ir technique for assigning structures in a study involving ring contraction-expansion of 3-hydroxypiperidine ? 2-hydroxymethylpyrrolidine systems and their ester derivatives. Nmr was not useful in studies of 3-aminopiperidines and 2-aminomethylpyrrolidines, but it could be applied to certain of their N-acyl derivatives. The nmr method was used to determine that esterification reactions of 1-methyl-3-(p-toluenesulfonyl)-piperidine and the sodium or potassium salts of some highly substituted carboxylic acids gave the ring-contracted pyrrolidine esters. In contrast, 1-methyl-3-aminopiperidine formed an amide with benzilic acid in which the piperidine ring remained unchanged. Aminolysis of methyl benzilate with 1-methyl-3-aminopiperidine resulted in a novel decarbonylation of the ester and isolation of benzophenone and l-methyl-3-formylamidopiperidine.