Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric Mannich synthesis of ?-amino esters by anion-binding catalysis.

ABSTRACT: We report a scalable, one-pot Mannich route to enantioenriched ?-amino esters by direct reaction of ?-chloroglycine ester as a practical imino ester surrogate. The reaction is promoted by a chiral aminothiourea, which is proposed to operate cooperatively by generating an iminium ion by chloride abstraction and an enolate by deprotonation, followed by highly stereoselective C-C bond formation between both reactive intermediates associated non-covalently within the catalyst framework.

SUBMITTER: Wasa M

PROVIDER: S-EPMC4183616 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric Mannich synthesis of α-amino esters by anion-binding catalysis.

Wasa Masayuki M Liu Richard Y RY Roche Stéphane P SP Jacobsen Eric N EN

Journal of the American Chemical Society 20140908 37

We report a scalable, one-pot Mannich route to enantioenriched α-amino esters by direct reaction of α-chloroglycine ester as a practical imino ester surrogate. The reaction is promoted by a chiral aminothiourea, which is proposed to operate cooperatively by generating an iminium ion by chloride abstraction and an enolate by deprotonation, followed by highly stereoselective C-C bond formation between both reactive intermediates associated non-covalently within the catalyst framework. ...[more]

PMID: 25178040

Similar Datasets

Photoredox Activation and Anion Binding Catalysis in the Dual Catalytic Enantioselective Synthesis of ?-Amino Esters.

Project description:The enantioselective oxidative C-H functionalization of tetrahydroisoquinoline derivatives is achieved through the merger of photoredox and asymmetric anion-binding catalysis. This combination of two distinct catalysis concepts introduces a potentially general approach to asymmetric transformations in oxidative photocatalysis.

| S-EPMC3842187 | biostudies-literature

Asymmetric Dearomatization of Phthalazines by Anion-Binding Catalysis.

Project description:A straightforward methodology for the enantioselective synthesis of 1,2-dihydrophthalazines via dearomatization of phthalazines by anion-binding catalysis has been developed. The process involves the Mannich-type addition of silyl ketene acetals to in situ generated N-acylphthalazinium chlorides using a tert-leucine derived thiourea as a H-bond donor catalyst. Ensuing selective and high-yielding transformations provide appealing dihydro- and tetrahydro-phthalazines, phthalazones, and piperazic acid homologues, en route to biologically relevant molecules.

| S-EPMC10729020 | biostudies-literature

Practical and highly enantioselective synthesis of beta-alkynyl-beta-amino esters through Ag-catalyzed asymmetric mannich reactions of silylketene acetals and alkynyl imines.

Project description:[reaction: see text] A readily available iso-leucine-based phosphine ligand is used to promote Ag-catalyzed Mannich reactions between silylketene acetals and various alkynyl imines. Reactions can be effected in the presence of 5 mol % catalyst, without the need for rigorous exclusion of air, and with commercially available solvents (without purification) to afford the desired beta-alkynyl-beta-amino esters in 84-94% ee and 61-91% isolated yield.

| S-EPMC2597397 | biostudies-literature

Organocatalytic asymmetric synthesis of α-amino esters from sulfoxonium ylides.

Project description:Described here is the first organocatalytic asymmetric N-H insertion reaction of α-carbonyl sulfoxonium ylides. Without a metal catalyst, this reaction represents an attractive complement to the well-established carbene insertion reactions. As a stable surrogate of diazocarbonyl compounds, sulfoxonium ylides reacted with a range of aryl amines to provide efficient access to α-aryl glycines with excellent enantiocontrol in the presence of a suitable chiral phosphoric acid catalyst. The high stability and weak basicity of sulfoxonium ylides not only enable this protocol to be user-friendly and practically useful, but also preclude catalyst decomposition, which is crucial to the excellent amenability to electron-poor amine nucleophiles. Detailed mechanistic studies indicated that the initial protonation is reversible and the C-N bond formation is rate-determining.

| S-EPMC8386753 | biostudies-literature

Enantioselective Synthesis of ?-Allyl Amino Esters via Hydrogen-Bond-Donor Catalysis.

Project description:We report a chiral-squaramide-catalyzed enantio- and diastereoselective synthesis of ?-allyl amino esters. The optimized protocol provides access to N-carbamoyl-protected amino esters via nucleophilic allylation of readily accessible ?-chloro glycinates. A variety of useful ?-allyl amino esters were prepared, including crotylated products bearing vicinal stereocenters that are inaccessible through enolate alkylation, with high enantioselectivity (up to 97% ee) and diastereoselectivity (>10:1). The reactions display first-order kinetic dependence on both the ?-chloro glycinate and the nucleophile, consistent with rate-limiting C-C bond formation. Computational analysis of the uncatalyzed reaction predicts an energetically inaccessible iminium intermediate, and a lower energy concerted SN2 mechanism.

| S-EPMC7293823 | biostudies-literature

Asymmetric synthesis of anti-β-amino-α-hydroxy esters via dynamic kinetic resolution of β-amino-α-keto esters.

Project description:A method for the asymmetric synthesis of enantioenriched anti-α-hydroxy-β-amino acid derivatives by enantioconvergent reduction of the corresponding racemic α-keto esters is presented. The requisite α-keto esters are prepared via Mannich addition of ethyl diazoacetate to imines followed by oxidation of the diazo group with Oxone. Implementation of a recently developed dynamic kinetic resolution of β-substituted-α-keto esters via Ru(II)-catalyzed asymmetric transfer hydrogenation provides the title motif in routinely high diastereo- and enantioselectivity.

| S-EPMC3766400 | biostudies-literature

Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction.

Project description:A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88-98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtained without column chromatography and recrystallization. The chiral phosphinyl auxiliary could be easily cleaved under acidic conditions.

| S-EPMC3999852 | biostudies-literature

Organocatalytic Enantioselective Mannich Reaction: Direct Access to Chiral β-Amino Esters.

Project description:An asymmetric Mannich reaction has been developed to generate chiral β-amino esters in good yields with excellent enantiomeric excesses (ee, up to 99%) using a chiral bifunctional thiourea catalyst derived from (R,R)-cyclohexyldiamine. This is the first report on the addition of 3-indolinone-2-carboxylates to N-Boc-benzaldimines generated in situ from α-amidosulfones, which proceeds under mild conditions.

| S-EPMC6648529 | biostudies-literature

One-Pot Asymmetric Nitro-Mannich/Hydroamination Cascades for the Synthesis of Pyrrolidine Derivatives: Combining Organocatalysis and Gold Catalysis.

Project description:The highly enantioselective preparation of trisubstituted pyrrolidine derivatives employing a one-pot nitro-Mannich/hydroamination cascade is reported. This cascade approach utilizes an asymmetric bifunctional organocatalytic nitro-Mannich reaction followed by a gold-catalyzed allene hydroamination reaction. The products are afforded in good yields and excellent diastereo- and enantioselectivities.

| S-EPMC3931436 | biostudies-literature

Direct Catalytic Asymmetric Synthesis of Trifluoromethylated γ-Amino Esters/Lactones via Umpolung Strategy.

Project description:Enabled by the discovery of new cinchonium salts and coadditives, a direct and efficient asymmetric access to trifluoromethylated γ-amino esters/lactones has been realized through the enantioselective and diastereoselective umpolung reaction of trifluoromethyl imines with acrylates or α,β-unsaturated lactones as carbon electrophiles. At 0.5-5.0 mol % catalyst loadings, the newly developed catalytic system activates a variety of imine substrates as unconventional nucleophiles to mediate highly chemo-, regio-, diastereo-, and enantioselective C-C bond forming reactions. The developed synthetic protocol represents an excellent strategy to target a series of versatile and enantiomerically enriched γ-amino esters/lactones in good to excellent yields from the readily available starting materials. Additionally, we found that the epi-vinyl catalysts based on cinchonidine and quinine promote a similarly high enantioselective reaction generating the opposite configuration of chiral products in a highly efficient manner, which allows convenient access to either the R- or S-enantiomer of the chiral amine products in high yields and excellent enantioselectivities.

| S-EPMC6467775 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data