[reaction: see text] A simple and efficient method for the synthesis of highly enantiomerically enriched beta-hydroxy-alpha-amino acid derivatives has been developed. Direct asymmetric aldol reactions of a glycine aldehyde (aminoacetaldehyde) derivative have been performed under organocatalysis using l-proline or (S)-5-pyrrolidine-2-yl-1H-tetrazole. The reactions afforded anti-beta-hydroxy-alpha-amino aldehydes in good yield with high diastereoselectivity (dr up to >100:1) and high enantioselectivity (up to >99.5% ee), which were easily transformed into beta-hydroxy-alpha-amino acid derivatives.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol0485417 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Catalytic Asymmetric Total Synthesis of (+)-Chamaecydin and (+)-Isochamaecydin and their Stereoisomers.
Angew Chem Int Ed Engl
January 2025
Changchun Institute of Applied Chemistry Chinese Academy of Sciences: Chang Chun Institute of Applied Chemistry Chinese Academy of Sciences, Jilin Province Key Lab of Green Chemistry and Process, CHINA.
A modular approach was developed for the first catalytic asymmetric total syntheses of naturally occurring C30 terpene quinone methides and their non-natural stereoisomers, which feature the presence of an unprecedented spiro[4.4]nonane-containing 6-6-6-5-5-3 hexacyclic skeleton. Resting on a chiral phosphinamide-catalyzed enantioselective reduction of 2,2-disubstituted cyclohexane-1,3-dione, a concise route for the synthesis of enantioenriched 6-6 bicyclic fragment was developed.
View Article and Find Full Text PDFIntramolecular Cascade Cyclization of Cyclobutanone: Asymmetric Construction of Cyclobutanone Fused Oxa-Spirocycles.
Org Lett
January 2025
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal By-pass Road, Bhauri, Bhopal 462066, India.
The successful implementation of a cascade reaction involving a cyclobutyl unit has posed a significant challenge in achieving ring-retentive functionalization because of the ring's sacrificial tendency. Herein, we have accomplished a cinchona-derived squaramide-catalyzed cascade reaction sequence, encompassing the desymmetrization of cyclobutanone, followed by an aldol reaction and, subsequently, a 1,4-addition step. This overall process offers a viable strategy to access architecturally fascinating oxa-spirocycles fused with cyclobutanone motifs in good yields with high optical purity.
View Article and Find Full Text PDFConvergent Total Synthesis of Ixabepilone and Its Analogues Enabled by Highly Efficient Asymmetric Hydrogenations.
Chemistry
December 2024
Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, China.
The convergent total synthesis of ixabepilone and its analogues in a 13-step longest linear sequence is reported. The crucial chiral centers at challenging C3-O, C8-C and C15-N positions on the scaffold of the ixabepilone were installed via highly efficient asymmetric hydrogenations (up to 95 % yield and up to 99 % e.e.
View Article and Find Full Text PDFEnzyme-Catalyzed Dynamic Kinetic Resolution for the Asymmetric Synthesis of 2,3-Dihydrobenzofuran Esters and Evaluation of Their Anti-inflammatory Activity.
Org Lett
December 2024
School of Pharmacy, Jiangsu University, Zhenjiang 212013, China.
Utilizing enzymes as biocatalysts, an alternative strategy has been developed for the highly enantioselective synthesis of chiral 2,3-dihydrobenzofuran (2,3-DHB) esters via the dynamic kinetic resolution of 2,3-dihydro-3-benzofuranols, which are generated from an intramolecular Aldol reaction. This protocol provides easy access to a series of 2,3-DHB ester derivatives, prodrugs, and allows for functional group transformations. Biological evaluation also indicates that some of the products exhibit potent anti-inflammatory activity.
View Article and Find Full Text PDFDiversity-Oriented Synthesis of Spirooxindoles via Asymmetric Organocatalytic Regiodivergent Cascade Reactions.
Org Lett
December 2024
Molecular Synthesis Center & Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
A regiodivergent strategy for the asymmetric diversity-oriented synthesis of spirooxindoles via organocatalytic cascade reactions is developed. Two regioselective pathways can be precisely controlled with different aminocatalysts in the reaction of 2-hydroxycinnamaldehydes and β,β-disubstituted 3-alkylidene oxindoles. The cascade vinylogous Michael/oxa-Michael/aldol reactions gave spiro-bridged oxindoles bearing two adjacent quaternary stereocenters, while the cascade oxa-Michael/Michael reactions gave spirooxindoles.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!