Asymmetric Conjugate Addition of Organocopper Reagents.
نویسندگان
چکیده
منابع مشابه
Catalytic asymmetric conjugate addition of Grignard reagents to chromones.
A highly regio- and enantioselective copper catalysed direct conjugate addition of Grignard reagents to chromones has been developed taking advantage of the reduced reactivity of the resulting magnesium enolates. This methodology tolerates a broad scope of alkyl Grignards including secondary alkyl magnesium reagents as well as functionalised chromones.
متن کاملAsymmetric conjugate addition of Grignard reagents to pyranones.
An efficient enantioselective synthesis of lactones was developed based on the catalytic asymmetric conjugate addition (ACA) of alkyl Grignard reagents to pyranones. The use of 2H-pyran-2-one for the first time in the ACA with Grignard reagents allows for a variety of further transformations to access highly versatile building blocks such as β-alkyl substituted aldehydes or β-bromo-γ-alkyl subs...
متن کاملTransmetalation Reactions Producing Organocopper Reagents
Organocopper reagents constitute a key class of organometallic reagents, with numerous applications in organic synthesis [1]. Their high reactivities and chemoselectivities have made them unique intermediates. Most reports use organocopper reagents of type 1 or 2, which are prepared from organolithiums. This transmetalation procedure confers optimal reactivity, but in many cases it permits only...
متن کاملCopper-catalyzed asymmetric conjugate addition of Grignard reagents to cyclic enones.
It is no longer necessary to use dialkylzinc reagents to obtain enantioselectivities >95% in the copper-catalyzed asymmetric conjugate addition of organometallic compounds to cyclic enones. We now report how this can be accomplished by using inexpensive and readily available Grignard reagents. Screening of bidentate ligands provided outstanding results with copper complexes of commercially avai...
متن کاملCopper-catalyzed asymmetric conjugate addition of organometallic reagents to extended Michael acceptors
The copper-catalyzed asymmetric conjugate addition (ACA) of nucleophiles onto polyenic Michael acceptors represents an attractive and powerful methodology for the synthesis of relevant chiral molecules, as it enables in a straightforward manner the sequential generation of two or more stereogenic centers. In the last decade, various chiral copper-based catalysts were evaluated in combination wi...
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ژورنال
عنوان ژورنال: Journal of Synthetic Organic Chemistry, Japan
سال: 1996
ISSN: 0037-9980,1883-6526
DOI: 10.5059/yukigoseikyokaishi.54.474