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Intramolecular Nucleophilic Substitution (intramolecular + nucleophilic_substitution)
Selected AbstractsUgi Multicomponent Reaction Followed by an Intramolecular Nucleophilic Substitution: Convergent Multicomponent Synthesis of 1-Sulfonyl 1,4-Diazepan-5-ones and of Their Benzo-Fused Derivatives.CHEMINFORM, Issue 31 2007Luca Banfi Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Aiding Factors in the Formation of Azaplatinacyclobutane Rings , X-ray and Crystal Structure of [Pt{CH(Ph)CH2NEt2 -,C,,N}(N,N,N,,N, -tetramethylethylenediamine)]+ and of Its Open-Chain PrecursorEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2007Giuseppe Lorusso Abstract The addition products 2 of a secondary amine to a coordinated olefin, in the cationic complexes [PtCl(,2 -CH2=CHR)(tmeda)]+ (tmeda = N,N,N,,N, -tetramethylethylenediamine; R = Me, 1a; Ph, 1b, H, 1c), undergo in basic medium an intramolecular nucleophilic substitution with elimination of the chlorido ligand and formation of an azaplatinacyclobutane ring 3. The ring-closing process occurs notwithstanding the absence of a labilizing ligand trans to the leaving chlorido ligand and of bulky substituents on the amino,ethanide chain. If the addition product 2 is a mixture of Markovnikov and anti-Markovnikov isomers, the ring-closing reaction is faster for the anti-Markovnikov form, and this leads to an increase of the relative amount of the anti-Markovnikov isomer in the cyclized species 3. The difference in the rate of formation of the azaplatinacyclobutane ring between the two isomers has been interpreted on the basis of a more favorable stereochemistry in the case of the anti-Markovnikov form. The X-ray crystal structures of [Pt{CH(Ph)CH2NEt2 -,C,,N}(tmeda)]+ (3bn) and of its open-chain precursor, [PtCl{CH(Ph)CH2NHEt2}(tmeda)]+ (2bn) fully support this hypothesis.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Low-energy collision-induced dissociation of sildenafil thiono analogues: gas-phase intramolecular nucleophilic substitution through ion-neutral complexes between a cationic substrate and a thione-containing neutral nucleophileRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 12 2005Jaeick Lee First page of article [source] Ring-Closure Reactions through Intramolecular Displacement of the Phenylselenonyl Group by Nitrogen Nucleophiles: A New Stereospecific Synthesis of N -Tosyl and N -Benzoyl-1,3-oxazolidin-2-ones from ,-Hydroxyalkyl Phenyl SelenidesCHEMISTRY - A EUROPEAN JOURNAL, Issue 7 2004Marcello Tiecco Prof. Abstract A new and convenient method for the stereospecific synthesis of variously substituted 1,3-oxazolidin-2-ones from the easily available ,-hydroxyalkyl phenyl selenides is presented. After transformation into the N -tosyl or N -benzoyl carbamates, the selenides were oxidized to the corresponding selenones. The key step of the process is the ring-closure reaction, which occurs by stereospecific intramolecular nucleophilic substitution of the selenone group by the nitrogen atom of the carbamate. Enantiomerically pure 1,3-oxazolidin-2-one derivatives can be easily prepared by using enantiomerically pure ,-hydroxyalkyl phenyl selenides as starting materials. [source] | ||||||||||