- Stereoselective Alkylation of Chiral Titanium(IV) Enolates with tert-Butyl Peresters
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Here, we present a new stereoselective alkylation of titanium(IV) enolates of chiral N-acyl oxazolidinones with tert-butyl peresters from Cα-branched aliphatic carboxylic acids, which proceeds through the decarboxylation of the peresters and the subsequent formation of alkyl radicals to produce the alkylated adducts with an excellent diastereoselectivity. Theoretical calculations account for the observed reactivity and the outstanding stereocontrol. Importantly, the resultant compounds can be easily converted into ligands for asymmetric and catalytic transformations.
- Pérez-Palau, Marina,Sanosa, Nil,Romea, Pedro,Urpí, Fèlix,López, Rosa,Gómez-Bengoa, Enrique,Font-Bardia, Mercè
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supporting information
p. 8852 - 8856
(2021/11/17)
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- Iron-Catalyzed Vinylic C?H Alkylation with Alkyl Peroxides
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A variety of alkyl peresters and alkyl diacyl peroxides, which are readily accessible from carboxylic acids, are utilized as general primary, secondary, and tertiary alkylating reagents for iron-catalyzed vinylic C?H alkylation of vinyl arenes, dienes, and 1,3-enynes. This transformation affords olefinic products in up to 98 % yield with high E/Z values. A broad range of functionalities, including carboxyl, boronic acid, methoxy, ester, amino, and halides, are tolerated. This protocol provides a facile approach to some olefins that are difficult to access, and hence, offers an alternative to existing systems. The synthetic utility of this method is demonstrated by late-stage functionalization of selected natural-product derivatives.
- Ge, Liang,Jian, Wujun,Zhou, Huan,Chen, Shaowei,Ye, Changqing,Yu, Fei,Qian, Bo,Li, Yajun,Bao, Hongli
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supporting information
p. 2522 - 2528
(2018/08/01)
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- Iron-Catalyzed Dehydrative Alkylation of Propargyl Alcohol with Alkyl Peroxides to Form Substituted 1,3-Enynes
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This paper reports a new method for the generation of substituted 1,3-enynes, whose synthesis by other methods could be a challenge. The dehydrative decarboxylative cascade coupling reaction of propargyl alcohol with alkyl peroxides is enabled by an iron catalyst and alkylating reagents. Primary, secondary, and tertiary alkyl groups can be introduced into 1,3-enynes, affording various substituted 1,3-enynes in moderate to good yields. Mechanistic studies suggest the involvement of a radical-polar crossover pathway.
- Ye, Changqing,Qian, Bo,Li, Yajun,Su, Min,Li, Daliang,Bao, Hongli
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supporting information
p. 3202 - 3205
(2018/06/11)
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- Method for producing acyl peroxides
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The invention relates to a method for producing acyl peroxides. According to said method, an acyl compound is reacted with an organic hydroperoxide and a base, the pH of the two-phase mixture so obtained is adjusted to 6 to 13, the obtained organic phase is extracted with an aqueous solution of a base and the aqueous extract is recirculated to the reaction step. The method according to the invention allows the recirculation of unreacted hydroperoxide to the reaction step.
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Page/Page column 5
(2010/02/17)
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- Continuous Method for Producing Acyl Peroxides
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The invention relates to a continuous method for producing acyl peroxides. According to said method, an acyl chloride, carboxylic acid anhydride or chloroformate is reacted with an organic hydroperoxide or hydrogen peroxide in at least two mixed reaction zones that are connected in series, the acyl compound, the peroxy compound and an aqueous solution of a base being supplied to the first reaction zone. The first reaction zone comprises a cycle for the two-phase reaction mixture via a heat exchanger in which the reaction mixture is cooled. The method allows the reaction to be carried out reliably and with high space-time yields.
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Page/Page column 5
(2010/03/02)
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- Oxidation of Esters with the Aluminum Tri-tert-butylate-tert-Butyl Hydroperoxide System
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The aluminum tri-tert-butylate-tert-butyl hydroperoxide system oxidizes under mild conditions (20°C) esters containing primary, secondary, and tertiary hydrogen atoms both in the acyl and alkoxy groups: isopropyl acetate, propionate, and chloroacetates, benzyl acetate and isobutyrate, and methyl and isobutyl phenylacetates. The reaction involves oxidation of the methylene and methine C-H bonds, nucleophilic addition to the carbonyl group, and ester interchange and is accompanied by cleavage of the carbon skeleton of the acyl group or the ester C-O bond.
- Zaburdaeva,Stepovik,Dodonov,Martynova
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p. 1902 - 1908
(2007/10/03)
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- Peroxy Esters. 8. Base-Catalyzed Rearrangement of Peroxy Esters: Formation of Alkoxyacetic Acid Derivatives
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p-Peroxyquinol esters derived from base-catalyzed oxygenation of 4-alkyl-2,6-tert-butylphenols followed by Schotten-Baumann acylation undergo a novel base-catalyzed rearrangement with t-BuOK in N,N-dimethylformamide to give p-quinoxyacetic acid derivatives in excellent yield.The same base-catalyzed rearrangement was also observed with tert-butyl peroxy esters.The base-catalyzed reaction of peroxy esters depended strongly on the nature of the acyl group in the esters and the base used and is suggested to involve homolysis of the peroxy bond.
- Nishinaga, Akira,Nakamura, Koichi,Matsuura, Teruo
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p. 3696 - 3700
(2007/10/02)
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- Batch process for manufacturing and purifying liquid organic peroxide by distillation
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A batch process for the manufacture of liquid organic peroxides, such as peroxy esters and diacyl peroxides, by reacting an acid chloride, a hydroperoxide and an alkali metal hydroxide uses a countercurrent, packed distillation column for recovering a purer, drier product with higher yield than previous batch drying processes.
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