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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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Stereospecific cross-coupling of N-tosylaziridines.
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fig57: Stereospecific cross-coupling of N-tosylaziridines.

Mentions: Recently, Takeda, Minakata,and co-workers reported a stereospecificSuzuki–Miyaura cross-coupling of arylaziridines. Ni-catalyzedcouplings of aziridines have previously been reported to proceed withstereochemical scrambling,212,213 so the authors insteadinvestigated Pd catalysts for this transformation. Although phosphineligands tended to promote β-hydride elimination, NHC ligandsfavored generation of the cross-coupled product, with C–C bondformation occurring at the benzylic position.214 Thus, treatment of aziridine 250 with a boronicacid and Pd-NHC precatalyst 252 furnished 251 in high yield and regioselectivity and with complete inversion ofconfiguration (Figure 57). The authors propose that SN2-type oxidative additionto 250 can form either metallacycle 253 oracyclic species 254. Transmetalation followed by reductiveelimination releases product 256 as a single enantiomerand regioisomer.


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)

Stereospecific cross-coupling of N-tosylaziridines.
© Copyright Policy
Related In: Results  -  Collection

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

fig57: Stereospecific cross-coupling of N-tosylaziridines.
Mentions: Recently, Takeda, Minakata,and co-workers reported a stereospecificSuzuki–Miyaura cross-coupling of arylaziridines. Ni-catalyzedcouplings of aziridines have previously been reported to proceed withstereochemical scrambling,212,213 so the authors insteadinvestigated Pd catalysts for this transformation. Although phosphineligands tended to promote β-hydride elimination, NHC ligandsfavored generation of the cross-coupled product, with C–C bondformation occurring at the benzylic position.214 Thus, treatment of aziridine 250 with a boronicacid and Pd-NHC precatalyst 252 furnished 251 in high yield and regioselectivity and with complete inversion ofconfiguration (Figure 57). The authors propose that SN2-type oxidative additionto 250 can form either metallacycle 253 oracyclic species 254. Transmetalation followed by reductiveelimination releases product 256 as a single enantiomerand regioisomer.

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.

AUTOMATICALLY GENERATED EXCERPT
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.