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    Diastereoselective α‐Alkylation of β‐Hydroxycarboxylic Esters through Alkoxide Enolates: Diethyl (2 S , 3 R )‐( + )‐3‐Allyl‐2‐Hydroxysuccinate from Diethyl ( S )‐( − )‐Malate
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    Abstract:
    Abstract Diastereoselective α‐alkylation of β‐hydroxycarboxylic esters through alkoxide enolates: diethyl (2 S , 3 R )‐( + )‐3‐allyl‐2‐hydroxysuccinate from diethyl ( S )‐( − )‐malate reactant: 9.51 g (50 mmol) of ( − )‐diethyl ( S )‐malate product: allylated product product: (2 S ,3 R )‐3‐allyl‐2‐hydroxysuccinic acid
    Keywords:
    Alkoxide
    Diethyl ether
    We report the first tris(alkoxide)V(III) complex to bind dinitrogen. Removal of THF from V(OR)(3)THF furnishes the highly reactive V(OR)(3) fragment, which binds dinitrogen to form [V(OR)(3)](2)(μ-N(2)) in the solid state. Dinitrogen is readily released upon dissolution of the complex. Structural and DFT studies are consistent with significant activation of N(2) when bound by the vanadium tris(alkoxide) platform.
    Alkoxide
    Citations (36)
    Abstract Alkylation of Cyclopropyl Ketones Reduction and Alkylation of α‐Substituted Ketones Substitutive Alkylation of α‐Halocarbonyl Compounds Substitutive Alkylation of β‐Halocarbonyl Compounds Substitutive Alkylation of α‐Diazocarbonyl Compounds Decarboxylation–Allylation of β‐Keto Acids and Esters
    Decarboxylation
    Abstract Two methods have been reported that allow yttrium alkoxides to be supported on porous silica and to be used afterward as heterogeneous catalysts in the ring‐opening polymerization of oxirane and ϵ‐caprolactone. In the two methods, [tris(hexamethyldisilyl)‐amide]yttrium {Y[N(SiMe 3 ) 2 ] 3 } is the metal alkoxide precursor. It is directly reacted with the silanol groups of the support, in the first method, and this is followed by alcoholysis of the unreacted amide groups. The flexibility of this method seems to be limited because the grafting density and the structure of the grafted Y alkoxide (less than one alkoxide by metal) are independent of the experimental conditions. In the second method, Y[N(SiMe 3 ) 2 ] 3 is first reacted with 1 or 2 equiv of alcohol with the formation of the mixed Y alkoxide/amide. The amide functions are used to attach Y to the support. This method is free from side reactions, quite reproducible, and well suited to support one type of active species (monoalkoxide or dialkoxide). Preliminary experiments with ϵ‐caprolactone polymerization have confirmed the activity of the supported Y alkoxide, whatever preparation method is used. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 569–578, 2003
    Alkoxide
    Silanol
    Amide
    Citations (14)
    Clear PZT sols have been prepared by controlled hydrolysis of Pb, Ti and Zr mixed alkoxide solutions in methoxy-ethanol. The water/methoxy-ethanol ratio which gives clear sol decreases with increasing alkoxide concentration at a constant alkoxide composition, and decrease as Zr alkoxide in Pb and Zr mixed alkoxide is substituted by Ti alkoxide. Sols dried at 70°C were analyzed by XRD, TEM and EDX. The particle size of sols was 10-40nm by TEM, which depends on the composition. The XRD result showed that dried powders are amorphous, which crystallize at above 600°C. EDX analysis of particles showed that PbTiO3 and PbZrO3 powders are chemically homogeneous at a particle level. On the other hand, PZT powder was less homogeneous.
    Alkoxide
    Citations (5)
    Alkylation is the transfer of an alkyl group (CnH2n+1) from one molecule (alkylating agent) to another where it can attach typically to carbon (C-alkylation), but also to oxygen (O-alkylation), nitrogen (N-alkylation), sulfur (S-alkylation) and phosphorous (P-alkylation) depending on the reaction conditions. This chapter discusses the importance of alkylation reactions, then looks at green improvements made by using solid acid catalysts, ionic liquids in Friedel–Crafts reactions, the atom economic borrowing hydrogen strategy and directed alkylation of C–H bonds using alkenes.
    Abstract KF/Al2O3 efficiently catalyzes N‐alkylation of heterocyclic, primary, and secondary amines and S‐alkylation of thiols with a variety of alkyl halides. The N‐alkylation and S‐alkylation adducts were produced in good to excellent yields and in short times.
    Primary (astronomy)
    Citations (22)