Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantio- and diastereoselective synthesis of (R,R)-beta-methoxytyrosine.

ABSTRACT: The nonproteinogenic amino acid (2R,3R)-beta-methoxytyrosine, a constituent of several cyclic depsipeptide natural products, was synthesized in protected form (8) from a readily available cinnamate ester in four steps and 62% overall yield with a greater than 28:1 er and 19:1 dr. This method provides a highly efficient, enantio- and diastereoselective synthesis of an important amino acid.

SUBMITTER: Cranfill DC

PROVIDER: S-EPMC2688733 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enantio- and diastereoselective synthesis of (R,R)-beta-methoxytyrosine.

Cranfill David C DC Lipton Mark A MA

Organic letters 20070803 18

The nonproteinogenic amino acid (2R,3R)-beta-methoxytyrosine, a constituent of several cyclic depsipeptide natural products, was synthesized in protected form (8) from a readily available cinnamate ester in four steps and 62% overall yield with a greater than 28:1 er and 19:1 dr. This method provides a highly efficient, enantio- and diastereoselective synthesis of an important amino acid. ...[more]

PMID: 17676746

Similar Datasets

Palladium(II)-catalyzed enantio- and diastereoselective synthesis of pyrrolidine derivatives.

Project description:A palladium-catalyzed enantio- and diastereoselective synthesis of pyrrolidine derivatives is described. Initial intramolecular nucleopalladation of the tethered protected amine forms the pyrrolidine moiety and a quinone methide intermediate. A second nucleophile adds intermolecularly to afford diverse products in high enantio- and diastereoselectivity.

| S-EPMC3459323 | biostudies-literature

Enantio- and diastereoselective synthesis of N-acetyl dihydrotetrafibricin methyl ester.

Project description:A highly diastereoselective synthesis of N-acetyl dihydrotetrafibricin methyl ester (34) is described. The synthesis features three enantioselective double allylboration reactions and an intramolecular hydrosilylation/Fleming-Tamao oxidation sequence to establish seven of the hydroxy-bearing stereocenters of 34. Especially noteworthy is the fragment-assembly double allyboration reaction of 2 and 7 using reagent 3, which provides the advanced intermediate 6 with >20:1 diastereoselectivity.

| S-EPMC3679187 | biostudies-literature

An Enantio- and Diastereoselective Chemoenzymatic Synthesis of ?-Fluoro ?-Hydroxy Carboxylic Esters.

Project description:The trans-o-hydroxybenzylidene pyruvate aldolase-catalysed reactions between fluoropyruvate and many (hetero)aromatic aldehydes yield aldol adducts without subsequent dehydration. Treatment of the reaction products with hydrogen peroxide yields the corresponding syn-configured ?-fluoro ?-hydroxy carboxylic acids which have >98?% ee. The overall chemoenzymatic approach, in which fluoropyruvate serves as a fluoroacetate equivalent, may be exploited in the synthesis of polar building blocks and fragments with potential value in drug discovery.

| S-EPMC5074308 | biostudies-literature

Highly enantio- and diastereoselective one-pot methods for the synthesis of halocyclopropyl alcohols.

Project description:The lack of methods for the stereoselective transfer of functionalized carbenoids is one of the most significant deficiencies of Simmons-Smith cyclopropanation reactions. Outlined herein are one-pot methods for the catalytic asymmetric synthesis of halocyclopropyl alcohols with up to four stereogenic centers from achiral starting materials. The first method involves asymmetric alkyl addition to a conjugated enal to generate an allylic alkoxide followed by tandem diastereoselective iodo-, bromo-, or chlorocyclopropanation to furnish halocyclopropyl alcohols. Enantioselectivities in these processes range from 89-99%, and dr's of >20:1 were achieved with all substrates optimized. The second method consists of an asymmetric vinylation of a saturated or aromatic aldehyde followed by a diastereoselective iodocyclopropanation to produce iodocyclopropyl alcohols with enantioselectivities between 86 and 99% and dr's of >20:1. These complementary methods enable the efficient synthesis of a variety of halocyclopropyl alcohols in one-pot procedures. Preliminary efforts to functionalize iodocyclopropanes involve reaction with an excess of LiCu(n-Bu)(2) to generate the cyclopropyl cuprate. This intermediate can be quenched with allyl bromides to generate the allylated cyclopropyl alcohols without loss of enantio- or diastereoselectivity.

| S-EPMC2646170 | biostudies-literature

Enantio- and Diastereoselective Synthesis of Homoallylic ?-Trifluoromethyl Amines by Catalytic Hydroalkylation of Dienes.

Project description:We describe a strategy for the enantio- and diastereoselective synthesis of homoallylic ?-trifluoromethyl amines by the catalytic hydroalkylation of terminal dienes. Trifluoromethyl-substituted isatin-derived azadienolate nucleophiles undergo ?-selective alkylation with a Pd-DTBM-SEGPHOS catalyst, which additionally promotes regioselective addition to the diene and delivers products in up to 86% yield, 10:1 dr, and 97.5:2.5 er.

| S-EPMC7079280 | biostudies-literature

Enantio- and diastereoselective conjugate borylation/Mannich cyclization.

Project description:Strategies to capitalize on enolate intermediates generated from stereoselective conjugate borylation to α,β-unsaturated carbonyl systems are surprisingly rare despite the ubiquity of Michael acceptors, and the potential to generate valuable scaffolds bearing multiple stereocenters. Herein, we report a mild and stereoselective copper-catalyzed conjugate borylation/Mannich cyclization reaction. This strategy is feasible with a broad range of Michael acceptors, and can be leveraged to generate versatile borylated tetrahydroquinoline scaffolds bearing three contiguous stereocenters. The synthetic potential of these complex heterocycles has been explored through a series of derivatization studies.

| S-EPMC8159378 | biostudies-literature

Enantio- and diastereoselective diarylmethylation of 1,3-dicarbonyl compounds.

Project description:A Cu-catalyzed enantio- and diastereoselective diarylmethylation of 1,3-dicarbonyl compounds is described. It is a successful example of constructing all-carbon quaternary stereocenters from 3 °C-H nucleophiles, a challenging topic in synthetic chemistry. In the present work, two contiguous stereocenters are constructed with high levels of stereoselectivity and atom economy. The broad scope of 1,3-dicarbonyl nucleophiles and the tolerance of a wide range of functional groups make this protocol of great importance in the synthesis of chiral diarylmethane compounds.

| S-EPMC8159382 | biostudies-literature

Enantio- and Diastereoselective Synthesis of Hydroxy Bis(boronates) via Cu-Catalyzed Tandem Borylation/1,2-Addition.

Project description:Catalytic enantioselective synthesis of 1-hydroxy-2,3-bisboronate esters through multicomponent borylation/1,2-addition is reported. Catalyst and substrates are readily available, form both a C-B and C-C bond, and generate up to three contiguous stereocenters. The reaction is tolerant of aryl, vinyl, and alkyl aldehydes and ketones in up to 95% yield, >20:1 dr, and 99:1 er. Intramolecular additions to aldehydes and ketones result in stereodivergent processes. The hydroxy bis(boronate) ester products are amenable to site-selective chemical elaboration.

| S-EPMC5837064 | biostudies-literature

Enantio- and Diastereoselective Synthesis of Functionalized Carbocycles by Cu-Catalyzed Borylative Cyclization of Alkynes with Ketones.

Project description:A single-pot Cu-catalyzed enantio- and diastereoselective tandem hydroboration/borylative cyclization of alkynes with ketones for the synthesis of carbocycles is reported. The reaction proceeds via desymmetrization and generates four contiguous stereocenters, including an all-carbon quaternary center. The method provides rapid access to [6,5]- and [5,5]-bicycles and cyclopentane products. Catalyst-controlled diastereoselectivity by selection of bisphosphine ligand is noted. Utility of the products is demonstrated by site- and chemoselective transformations that afford valuable alkenyl and allyl organoborons.

| S-EPMC6702961 | biostudies-literature

Enantio- and Diastereoselective Suzuki-Miyaura Coupling with Racemic Bicycles.

Project description:Herein, we describe a rhodium-catalyzed enantio- and diastereoselective Suzuki-Miyaura cross-coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl, heteroaryl, and alkenyl boronic acids and gives access to functionalized bicyclic cyclopentenes, which can be converted into other five-membered-ring scaffolds with up to five contiguous stereocenters. Preliminary mechanistic studies suggest that these reactions occur with overall retention of the relative stereochemistry and are enantioconvergent for pseudo-symmetric allylic chloride starting materials. In addition, a bicyclic allylic chloride starting material without pseudo-symmetry undergoes a highly enantioselective regiodivergent reaction.

| S-EPMC6771587 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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