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Regioselective Reactions (regioselective + reaction)

Distribution by Scientific Domains

Chemistry	100%

Distribution within Chemistry

Organic Chemistry	57%
General & Introductory Chemistry	42%

Selected Abstracts

ChemInform Abstract: Regioselective Reaction of 2-Hydroxyiminoimidazolidine-O-sulfonate with Benzyl Bromides.

CHEMINFORM, Issue 7 2009
J. Saczewski
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 of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Regioselective Reactions on a Chiral Substrate Controlled by the Configuration of a Chiral Catalyst

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010
Raju Ranjith Kumar
Abstract A racemic mixture may be partially transformed in the presence of a chiral catalyst by kinetic resolution and formation of products with new structural features. If the starting material is fully consumed the products may still be enantiomerically enriched. The situation is summarized in the Introduction. A brief discussion on the regioselective transformations occurring on a racemic mixture under the influence of a chiral catalyst is presented in Section 2. Often stereo-differences occur, each enantiomer of the starting material resulting in a different product. It allows one to predict what the behaviour of some enantiopure substrates should be in presence of each of the enantiomers of a chiral catalyst. Many examples are presented in Section 3. The chiral substrates under consideration have two different reacting sites, usually of the same nature (OH, CC, allylic positions, CH for carbene insertion, epoxide fragment, etc.). In some cases the absolute configuration of the catalyst allows an excellent control of the regioselectivity. This approach is promising for the selective transformation of chiral molecules. [source]

Regioselective Reactions of ,-Aminovinyl Trifluoromethyl Ketones with Tosyl Isocyanate.

CHEMINFORM, Issue 26 2003
Natalie V. Lyutenko
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Preparation and Regioselective Reactions of Novel gem-Difluorinated Vinyloxiranes with Some Organometallic Reagents.

CHEMINFORM, Issue 12 2003
Takashi Yamazaki
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Mechanism of Remote Conjugate Addition of Lithium Organocuprates to Polyconjugated Carbonyl Compounds

CHEMISTRY - AN ASIAN JOURNAL, Issue 3 2006
Naohiko Yoshikai
Abstract Regioselective reaction of a lithium organocuprate (R2CuLi) and a polyconjugated carbonyl compound affords a remote-conjugate-addition product. This reaction proceeds particularly cleanly when the conjugation is terminated by a CC triple bond. The reaction pathways and the origin of the regioselectivity of this class of transformations are explored with the aid of density functional calculations. The outline of the reaction pathway is as follows. An initially formed ,-cuprio(III) enolate intermediate undergoes smooth copper migration along the conjugated system. This process takes place faster than reductive elimination of intermediary ,/,-allylcopper(III) species, since the latter reaction disrupts the conjugation in the substrate and hence is not preferred. The copper migration to the acetylenic terminal affords a ,/,-allenylcopper(III) intermediate, which undergoes facile and selective CC bond forming reductive elimination at the terminal carbon atom. The present mechanistic framework shows good agreement with some pertinent experimental data, including 13C,NMR chemical shifts and kinetic isotope effects. [source]

7-Iodo-5-aza-7-deazaguanine: Syntheses of Anomeric D - and L -Configured 2-Deoxyribonucleosides

HELVETICA CHIMICA ACTA, Issue 9 2004
Wenqing Lin
Iodination of N2 -isobutyryl-5-aza-7-deazaguanine (7) with N -iodosuccinimide (NIS) gave 7-iodo- N2 -isobutyryl-5-aza-7-deazaguanine (8) in a regioselective reaction (Scheme,1). Nucleobase-anion glycosylation of 8 with 2-deoxy-3,5-di- O -toluoyl- , - D - or , - L - erythro -pentofuranosyl chloride furnished anomeric mixtures of D - and L -nucleosides. The anomeric D -nucleosides were separated by crystallization to give the , - D -anomer and , - D -anomer with excellent optical purity. Deprotection gave the 7-iodo-5-aza-7-deazaguanine 2,-deoxyribonucleosides 3 (, - D; ,99% de) and 4 (, - D; ,99% de). The reaction sequence performed with the D -series was also applied to L -nucleosides to furnish compounds 5 (, - L; ,99% de) and 6 (, - L; ,95% de). [source]

Preparation of [5,6]- and [6,6]-Oxahomofullerene Derivatives and Their Interconversion by Lewis Acid Assisted Reactions of Fullerene Mixed Peroxides

CHEMISTRY - A EUROPEAN JOURNAL, Issue 18 2005
Shaohua Huang
Abstract [60]Fullerene mixed peroxides C60(O)(OOtBu)4 exhibit chemo- and regioselective reactions under mild conditions. The epoxy moiety is opened by ferric chloride to form vicinal hydroxy chloride C60Cl(OH)(OOtBu)4. BF3 is also effective in opening the epoxy moiety. The OO bond of the fullerene mixed peroxide is cleaved by aluminum chloride to form both [5,6]- and [6,6]-fullerene hemiketals (oxohomo[60]fullerenes). A Hock-type rearrangement is proposed for the formation of the hemiketals, in which a fullerene CC bond is cleaved. Lewis acids and/or visible light can initiate isomerization of the hemiketal isomers. Single-crystal X-ray analysis and theoretical calculations confirmed the results. [source]