Asymmetric alkylation of carbonyl compounds with lithium or sodium tetraalkylaluminates modified by chiral aminoalcohols

Boireau, G.; Abenhaïm, D.; Henry-Basch, Erica

doi:10.1016/0040-4020(79)85044-9

Cited by 17 publications

(2 citation statements)

References 30 publications

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“…Furthermore, our optimization studies revealed that the addition of AlCl 3 provided a slightly higher reaction yield compared to the additive-free version, which could be explained by its Lewis acidity, corresponding to its ability to activate the aldehyde/ oxazolidinone and/or to bind the released oxazolidone anion. 50,51 Under these reaction conditions, we were pleased to observe that a syn-configured 1,4-dicarbonyl could be smoothly converted to the trans/trans γ-C-substituted lactone 11a in excellent yield (93%) and with good diastereoselectivity (d.r. = 81:17:2:nd).…”

Section: ■ Results and Discussionmentioning

confidence: 96%

“…The desired breakthrough was achieved only when DCM was employed as a cosolvent, which simultaneously ensured good diastereoselectivities and high yields. Furthermore, our optimization studies revealed that the addition of AlCl 3 provided a slightly higher reaction yield compared to the additive-free version, which could be explained by its Lewis acidity, corresponding to its ability to activate the aldehyde/oxazolidinone and/or to bind the released oxazolidone anion. , …”

Section: Resultsmentioning

confidence: 99%

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Stereodivergent Synthesis of 1,4-Dicarbonyl Compounds through Sulfonium Rearrangement: Mechanistic Investigation, Stereocontrolled Access to γ-Lactones and γ-Lactams, and Total Synthesis of Paraconic Acids

G.-Simonian,

Spieß,

Riomet

et al. 2024

J. Am. Chem. Soc.

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Although simple γ-lactones and γ-lactams have received considerable attention from the synthetic community, particularly due to their relevance in biological and medicinal contexts, stereoselective synthetic approaches to more densely substituted derivatives remain scarce. The in-depth study presented herein, showcasing a straightforward method for the stereocontrolled synthesis of γ-lactones and γ-lactams, builds on and considerably expands the stereodivergent synthesis of 1,4-dicarbonyl compounds by a ynamide/vinyl sulfoxide coupling. A full mechanistic and computational study of the rearrangement was conducted, uncovering the role of all of the reaction components and providing a rationale for stereoselection. The broad applicability of the developed tools to streamlining synthesis is demonstrated by concise enantioselective total syntheses of (+)-nephrosteranic acid, (+)-rocellaric acid, and (+)-nephromopsinic acid.

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Section: ■ Results and Discussionmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Stereodivergent Synthesis of 1,4-Dicarbonyl Compounds through Sulfonium Rearrangement: Mechanistic Investigation, Stereocontrolled Access to γ-Lactones and γ-Lactams, and Total Synthesis of Paraconic Acids

G.-Simonian,

Spieß,

Riomet

et al. 2024

J. Am. Chem. Soc.

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Asymmetric addition of n‐butyllithium to aldehydes by chiral polymers having acetoxybornyl moieties

Liu

Kuo

1992

Angew. Makromol. Chem.

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Optically active (+)-2-endo-acetoxy-5-endo-bornyl methacrylate (ABMA) was prepared from (+)-camphor. The free-radical homopolymerization of ABMA and its copolymerization with achiral methyl methacrylate (MMA) or styrene (St) were carried out with 2,2'-azoisobutyronitrile in benzene. Effects of temperature and reaction time on the copolymerization were discussed. The monomer reactivity ratios (r,, r2) for poly(ABMA-co-MMA) and poly(ABMA-co-St) as well as Q and e values for the chiral ABMA in the copolymerization systems were evaluated by the Fineman-Ross method. It was found that the absolute value of the specific rotation of poly(ABMA-co-MMA) increased with increasing ABMA unit content. A small deviation from linearity was observed, which suggests that asymmetry is not introduced into the copolymer main chain. Temperature and solvent effects on the specific rotation of the chiral homopolymer and copolymers were investigated. The results suggest that the chiral polymers synthesized in this investigation did not show a strong preference for a particular helical conformation. Applications of the chiral polymers on the asymmetric addition of nbutyllithium to aldehydes were investigated. The effect of temperature and aldehydes on the asymmetric addition were also discussed. ZUSAMMENFASSUNG:Optisch aktives ( + )-2-endo-Acetoxy-5-endo-bornylmethacrylat (ABMA) wurde aus (+)-Campher hergestellt und in Benzol radikalisch homo-bzw. mit achiralem Methylmethacrylat (MMA) bzw. Styrol (St) copolymerisiert. Der EinfluB von Temperatur und Reaktionszeit auf den Polymerisationsverlauf wird diskutiert. Die Copolymerisationsparameter (r, und r2, nach Fineman-Ross) fur Poly(ABMA-co-MMA) und Poly(ABMA-co-St) sowie die Q-und e-Werte fur ABMA wurden berechnet.Der Absolutwert der spezifischen Drehung von Poly(ABMA-co-MMA) nimmt mit steigendem ABMA-Gehalt im Copolymeren zu. Eine geringe Abweichung von der Linearitat deutet darauf hin, daB die Copolymerhauptkette nicht asymmetrisch ist. Aus der Temperatur-und Lijsungsmittelabhangigkeit der spezifischen Drehung der be-schriebenen Homo-und Copolymeren laBt sich schlierjen, da13 diese nicht in einer speziellen helikalen Konformation vorliegen. Die Eignung der chiralen Polymeren a k Katalysatoren fur die asymmetrische Addition von Butyllithium an verschiedene Aldehyde in Abhangigkeit von der Temperatur wurde untersucht.

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Chiral Lithium Amido Zincates for Enantioselective 1,2‐Additions: Auto‐assembling Reagents Involving a Fully Recyclable Ligand

Rouen

Chaumont

Barozzino‐Consiglio

et al. 2018

Chemistry A European J

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A methodology consisting in carrying out enantioselective nucleophilic 1,2-additions (ee values up to 97 %) from cheap, easily accessible, and never described before, chiral lithium amido zincates is presented. These multicomponent reactants auto-assemble when mixing, in a 1:1 ratio, a homoleptic diorganozinc (R Zn) with a chiral lithium amide (CLA). The latter, obtained after a single reductive amination, plays the role of the chiral inductor and is fully recoverable thanks to a simple acid-base wash, allowing being recycled and re-use without loss of stereochemical information.

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Asymmetric alkylation of carbonyl compounds with lithium or sodium tetraalkylaluminates modified by chiral aminoalcohols

Cited by 17 publications

References 30 publications

Stereodivergent Synthesis of 1,4-Dicarbonyl Compounds through Sulfonium Rearrangement: Mechanistic Investigation, Stereocontrolled Access to γ-Lactones and γ-Lactams, and Total Synthesis of Paraconic Acids

Stereodivergent Synthesis of 1,4-Dicarbonyl Compounds through Sulfonium Rearrangement: Mechanistic Investigation, Stereocontrolled Access to γ-Lactones and γ-Lactams, and Total Synthesis of Paraconic Acids

Asymmetric addition of n‐butyllithium to aldehydes by chiral polymers having acetoxybornyl moieties

Chiral Lithium Amido Zincates for Enantioselective 1,2‐Additions: Auto‐assembling Reagents Involving a Fully Recyclable Ligand

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