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Enantioselective and Enantiospecific Transition-Metal-Catalyzed Cross-Coupling Reactions of Organometallic Reagents To Construct C-C Bonds.

Cherney AH, Kadunce NT, Reisman SE - Chem. Rev. (2015)

View Article: PubMed Central - PubMed

Affiliation: The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.

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reagents in asymmetric alkyl cross-coupling reactions, with Hayashi, a single example of an asymmetric cross-coupling between sec-alkyl organic halides and organosilicon reagents has been reported stereoconvergent cross-coupling reactions between sec-alkyl electrophiles and either C(sp)- or C(sp)-hybridized organometallic reagents, Sestelo, Sarandeses, (Scheme 9a)... This result and π-allylmetal complex... Unselective reductive selectivity for the (Z)-alkene in most cases; MeMgBr resulted in decreased regioselectivity... increasing the C1–C1′ separation and disfavoring 1,1′ reductive elimination... use in asymmetric allylic alkylation reactions: any successful transformations the allenylmetal and its isomeric propargylmetal species prior to reductive elimination... the analogous asymmetric cross-coupling reactions of tert-alkyl partners represent a largely undeveloped area of great synthetic

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Atroposelectivering openings of dinaphthothiophene.
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fig92: Atroposelectivering openings of dinaphthothiophene.

Mentions: Exploiting the ability of Ni to insert into the C–Sbondof benzothiophene, Hayashi and co-workers explored the Ni-catalyzedKumada–Corriu coupling of 474 with aryl Grignardreagents to give enantioenriched biaryl thiols (Figure 92a).351,352 Dinaphthothiophene (474) is generally considered tobe an achiral compound because of the low barrier to flipping aboutthe axial axis of symmetry. When PHOX ligand L52 wasemployed, the Ni-catalyzed ring-opening/cross-coupling proceeded inhigh yield and ee. The atroposelectivity was strongly influenced bythe identity of the Grignard reagent; alkylmagnesium reagents reactedwith poor selectivity. On the basis of this observation, the authorspropose that the reaction proceeds by a DYKAT of the rapidly equilibratingoxidative addition products (M)-476 and(P)-476, in which the transmetalationstep sets the axial chirality. The reaction could also be extendedto dibenzothiophene coupling partners to generate axially chiral biphenylproducts. Despite efforts to improve the selectivity of the reactionbetween 474 and alkyl Grignard reagents, the best conditionsidentified to date, which utilize chiral phosphine L106, deliver 477 with only moderate enantioselectivity(Figure 92b).


Enantioselective and Enantiospecific Transition-Metal-Catalyzed Cross-Coupling Reactions of Organometallic Reagents To Construct C-C Bonds.

Cherney AH, Kadunce NT, Reisman SE - Chem. Rev. (2015)

Atroposelectivering openings of dinaphthothiophene.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4566132&req=5

fig92: Atroposelectivering openings of dinaphthothiophene.
Mentions: Exploiting the ability of Ni to insert into the C–Sbondof benzothiophene, Hayashi and co-workers explored the Ni-catalyzedKumada–Corriu coupling of 474 with aryl Grignardreagents to give enantioenriched biaryl thiols (Figure 92a).351,352 Dinaphthothiophene (474) is generally considered tobe an achiral compound because of the low barrier to flipping aboutthe axial axis of symmetry. When PHOX ligand L52 wasemployed, the Ni-catalyzed ring-opening/cross-coupling proceeded inhigh yield and ee. The atroposelectivity was strongly influenced bythe identity of the Grignard reagent; alkylmagnesium reagents reactedwith poor selectivity. On the basis of this observation, the authorspropose that the reaction proceeds by a DYKAT of the rapidly equilibratingoxidative addition products (M)-476 and(P)-476, in which the transmetalationstep sets the axial chirality. The reaction could also be extendedto dibenzothiophene coupling partners to generate axially chiral biphenylproducts. Despite efforts to improve the selectivity of the reactionbetween 474 and alkyl Grignard reagents, the best conditionsidentified to date, which utilize chiral phosphine L106, deliver 477 with only moderate enantioselectivity(Figure 92b).

View Article: PubMed Central - PubMed

Affiliation: The Warren and Katharine Schlinger Laboratory for Chemistry and Chemical Engineering, Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.

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Please rate it.

reagents in asymmetric alkyl cross-coupling reactions, with Hayashi, a single example of an asymmetric cross-coupling between sec-alkyl organic halides and organosilicon reagents has been reported stereoconvergent cross-coupling reactions between sec-alkyl electrophiles and either C(sp)- or C(sp)-hybridized organometallic reagents, Sestelo, Sarandeses, (Scheme 9a)... This result and π-allylmetal complex... Unselective reductive selectivity for the (Z)-alkene in most cases; MeMgBr resulted in decreased regioselectivity... increasing the C1–C1′ separation and disfavoring 1,1′ reductive elimination... use in asymmetric allylic alkylation reactions: any successful transformations the allenylmetal and its isomeric propargylmetal species prior to reductive elimination... the analogous asymmetric cross-coupling reactions of tert-alkyl partners represent a largely undeveloped area of great synthetic

No MeSH data available.