synthesis of -amino acids via asymmetric phase transfer

  • enantioselective synthesis of (r)- and (s)-α-alkylcysteines

    Enantioselective Synthesis of (R)- and (S)-α-Alkylcysteines

    Highly Enantioselective Synthesis of (S)-α-Alkyl-α,β-diaminopropionic Acids via Asymmetric Phase-Transfer Catalytic Alkylation of 2-Phenyl-2-imidazoline-4-carboxylic Acid tert-Butyl Esters. Organic Letters 2009, 11 (16) , 3738-3741. DOI: 10.1021/ol9013552.

  • highly enantioselective synthesis of (s)-α-alkyl-α,β

    Highly Enantioselective Synthesis of (S)-α-Alkyl-α,β

    An efficient enantioselective synthetic method for (S)-α-alkyl-α,β-diaminopropionic acid is reported. The asymmetric phase-transfer catalytic alkylation of N(1)-Boc-2-phenyl-2-imidazoline-4-carboxylic acid tert -butyl ester in the presence of chiral quaternary ammonium catalyst gave the corresponding alkylated products (93−98% ee) which could be transformed to enantioenriched α-alkyl-α

  • bifunctional phase-transfer catalysis in the asymmetric

    Bifunctional phase-transfer catalysis in the asymmetric

    Asymmetric cascade reaction of 2-cyanobenzaldehyde under phase-transfer conditions. As already discussed [21–23], the bifunctional nature of organocatalysts plays an important role in this reaction to attain satisfactory levels of enantioselectivity.

  • asymmetric phase‐transfer‐catalyzed intramolecular n

    Asymmetric Phase‐Transfer‐Catalyzed Intramolecular N

    Stéphane Lebrun, Romain Sallio, Mélanie Dubois, Francine Agbossou‐Niedercorn, Eric Deniau, Christophe Michon, Chiral Phase‐Transfer‐Catalyzed Intramolecular aza‐Michael Reactions for the Asymmetric Synthesis of Isoindolinones, European Journal of Organic Chemistry, 10.1002/ejoc.201403573, 2015, 9, (1995-2004), (2015).

  • asymmetric one-pot transformation of isoflavones to

    Asymmetric one-pot transformation of isoflavones to

    Here, the authors report the asymmetric syntheses of several natural isoflavonoids, including (−)-glyceollin I and (−)-glyceollin II, by means of an asymmetric transfer hydrogenation (ATH

  • a new approach towards the asymmetric fluorination of alkenes

    A New Approach towards the Asymmetric Fluorination of Alkenes

    Dixit Parmar, Modhu Sudan Maji, Magnus Rueping, Catalytic and Asymmetric Fluorolactonisations of Carboxylic Acids through Anion Phase Transfer, Chemistry – A European Journal, 10.1002/chem.201303385, 20, 1, (83-86), (2013).

  • asymmetric electrophilic fluorination using an anionic chiral

    Asymmetric Electrophilic Fluorination Using an Anionic Chiral

    The discovery of distinct modes of asymmetric catalysis has the potential to rapidly advance chemists’ ability to build enantioenriched molecules. As an example, the use of chiral cation salts as phase-transfer catalysts for anionic reagents has enabled a vast set of enantioselective transformations. Here, we present evidence that a largely overlooked analogous mechanism wherein a chiral

  • asymmetric fluorination of enamides: access to -fluoroimines

    Asymmetric Fluorination of Enamides: Access to -Fluoroimines

    Selectfluor, and anionic phase-transfer catalysts based on chiral phosphoric acids, specifically TRIP and C 8-TRIP (eq 1). 10 As a powerful application of this new strategy we sought to apply this concept to the enantioselective synthesis of α-fluoroimines. Specifically, enamides and ene−carbamates have seen much

  • (pdf) synthesis of a new chiral phase-transfer catalysts

    (PDF) Synthesis of a new chiral phase-transfer catalysts

    A new chiral phase-transfer catalyst (3S,4S)-1-benzyl-1-methyl-3,4- pyrrolidin-diol-onium iodide (2) synthesized, is found to be more active than the conventional tetraaklylammonium salts in

  • synthesis of bioactive quinazolin-4(3h)-one derivatives via

    Synthesis of bioactive quinazolin-4(3H)-one derivatives via

    Synthesis of bioactive quinazolin-4(3H)-one derivatives via microwave activation tailored by phase-transfer catalysis Yaser A. El-Badry yaser75moemen@yahoo.com 1 , 2 , Mahr A. El-Hashash 3 and Khalil Al-Ali 4

  • efficient asymmetric synthesis of s,s-2-methylsulfanyl-2

    Efficient Asymmetric Synthesis of S,S-2-methylsulfanyl-2

    Keywords: asymmetric synthesis; indanone; indanol; phase-transfer catalysis 1. INTRODUCTION The term "phase-transfer catalysis" (PTC) was first used by Starks [1] in 1971 and can be defined as "a synthetic method that accelerates or causes reactions between substances that are placed in contact via one transfer agent or catalyst."

  • chiral phase transfer catalysis in the asymmetric synthesis

    Chiral Phase Transfer Catalysis in the Asymmetric Synthesis

    In this work we report our endeavors toward the development of an asymmetric synthesis of a 3,3-disubstituted isoindolinone, dimethyl 2-(1-methyl-3-oxoisoindolin-1-yl)malonate, via asymmetric cascade reaction of 2-acetylbenzonitrile with dimethylmalonate and the determination of its absolute configuration (AC) by vibrational circular dichroism (VCD).