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Quaternary Stereogenic Centers (quaternary + stereogenic_center)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Catalytic Enantioselective Dieckmann-Type Annulation: Synthesis of Pyrrolidines with Quaternary Stereogenic Centers,

ANGEWANDTE CHEMIE, Issue 10 2010
Jonathan
Neues gelernt: Eine Cyclisierung vom Dieckmann-Typ ermöglichte die Synthese der Titelverbindungen mit bis zu 96,%,ee (siehe Schema; Bn=Benzyl). Das Vorliegen einer ,-koordinierenden Einheit im Substrat führt zu einer Konkurrenz zwischen Cyclisierung und Eliminierung, die durch die Art des chiralen Liganden beeinflusst wird. Eine mechanistische Erklärung für diese Beobachtungen wird vorgestellt. [source]

ChemInform Abstract: Stereoselective Construction of Halogenated Quaternary Stereogenic Centers via Catalytic Asymmetric Diels,Alder Reaction.

CHEMINFORM, Issue 35 2010
Kazutaka Shibatomi
No abstract is available for this article. [source]

ChemInform Abstract: Rhodium(I)-Catalyzed Enantioselective Activation of Cyclobutanols: Formation of Cyclohexane Derivatives with Quaternary Stereogenic Centers.

CHEMINFORM, Issue 29 2010
Tobias Seiser
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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]

ChemInform Abstract: Rhodium(I)-Catalyzed Enantioselective Activation of Cyclobutanols: Formation of Cyclohexane Derivatives with Quaternary Stereogenic Centers.

CHEMINFORM, Issue 29 2010
Tobias Seiser
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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]

All-Carbon Quaternary Stereogenic Centers by Enantioselective Cu-Catalyzed Conjugate Additions Promoted by a Chiral N-Heterocyclic Carbene.

CHEMINFORM, Issue 23 2007
M. Kevin Brown
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]

Enantioselective Electrophilic Amination of ,-Cyanothioacetates with Azodicarboxylates Catalyzed by an Axially Chiral Guanidine Base

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
Masahiro Terada
Abstract An enantioselective electrophilic amination of ,-substituted cyanothioacetates with azodicarboxylate is demonstrated using an axially chiral guanidine as a chiral Brønsted base catalyst. The corresponding product, having a quaternary stereogenic center at the ,-carbon atom, is formed in excellent enantioselectivity. [source]

A Tandem, Nitroalkene Conjugate Addition/[3+2] Cycloaddition Approach to the Synthesis of the Pentacyclic Core of (±)-Scandine

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16-17 2006
Scott
Abstract The complete pentacyclic core of the melodinus alkaloid scandine has been synthesized. The synthetic strategy features two key steps: (1) a tandem nitroalkene conjugate addition/[3+2] cycloaddition of the resulting silyl nitronate and (2) an intramolecular Heck reaction of an aryl iodide with a ,-disubstituted allylic alcohol which set a highly congested, quaternary stereogenic center with the concomitant formation of an aldehyde. Intramolecular reductive amination with this aldehyde completed the pentacyclic core. [source]