Enantioselective Synthesis of .ALPHA.-Amino Acids by Chiral Phase-Transfer Catalysis
نویسندگان
چکیده
منابع مشابه
Catalytic enantioselective fluorination of beta-keto esters by phase-transfer catalysis using chiral quaternary ammonium salts.
[reaction: see text] The catalytic enantioselective electrophilic fluorination promoted by quaternary ammonium salt from cinchonine as a phase-transfer catalyst is described. Treatment of beta-keto esters with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding alpha-fluoro beta-keto esters in exellent yields with good to moderate enantiom...
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We report a catalytic enantioselective electrophilic fluorination of alkenes to form tertiary and quaternary C(sp3)-F bonds and generate β-amino- and β-aryl-allylic fluorides. The reaction takes advantage of the ability of chiral phosphate anions to serve as solid-liquid phase transfer catalysts and hydrogen bond with directing groups on the substrate. A variety of heterocyclic, carbocyclic, an...
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A palladium-catalyzed three-component coupling of α-olefins, aryldiazonium salts, and bis(pinacolato)diboron affords direct access to chiral benzylic boronic esters. This process is rendered highly enantioselective using an unprecedented example of cooperative chiral anion phase transfer and transition-metal catalysis.
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Chiral anion phase-transfer catalysis has enabled the direct and highly enantioselective fluorinative dearomatization of phenols catalyzed by a BINOL-derived phosphate. The process efficiently transforms simple, readily available phenols into fluorinated chiral small molecules bearing reactive functionality under ambient reaction conditions with high enantioselectivity. The close relationship o...
متن کاملChiral Phase-transfer Catalysis (cptc) by Modified Cinchona Alkaloids
INTRODUCTION Phase-transfer catalysis (PTC) involves the use of environmentally benign organocatalysts, mild reaction conditions, and simple experimental procedures that are insensitive to air/moisture and amenable to large-scale processes. Furthermore, the use of inexpensive inorganic bases such as NaOH in place of expensive moisture-sensitive hydride, alkoxide and amide bases makes PTC an att...
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ژورنال
عنوان ژورنال: Journal of Synthetic Organic Chemistry, Japan
سال: 2003
ISSN: 0037-9980,1883-6526
DOI: 10.5059/yukigoseikyokaishi.61.1195