Diastereoselective reactions between (S)-phenylglycinol-derived oxazolidines and two unsaturated organolithium reagents afforded chiral beta-amino alcohols having vinyl and alkynylsilane moieties. When the same reactions were performed in the presence of titanium isopropoxide, a dramatic change of regioselectivity was observed, from the alpha- to the gamma-position, thus producing beta-amino alcohols with allyl or allenylsilane functions. A rationalization of the observed diastereoselectivity was suggested for each case.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jo010779a | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Sulfonated asphaltene as a highly efficient catalyst for the Mannich reaction with excellent diastereoselectivity and recyclability.
Sci Rep
December 2024
Department of Organic and Polymer Chemistry, Faculty of Chemistry, Kharazmi University, Tehran, 15719-14911, Iran.
This study investigates the repurposing of asphaltene, a petroleum waste product, as a catalyst for organic reactions. Sulfonated asphaltene was synthesized and evaluated for its efficacy in catalyzing the Mannich reaction, displaying notable diastereoselectivity and operating effectively under mild conditions. Characterization of the catalyst's chemical composition, structure, and thermal stability was conducted using FT-IR, TGA, XRD, CHN, BET-BJH, SEM, and EDS analyses.
View Article and Find Full Text PDFCoordination-Assisted Ni-Catalyzed Regio- and Enantioselective 1,2-Borylalkylation of Unactivated Alkenes.
Org Lett
December 2024
College of Chemistry and Materials Science, Hengyang Normal University, Hengyang 421000, People's Republic of China.
Herein we successfully utilize various directing groups to achieve a ligand-enabled nickel-catalyzed 1,2-borylalkylation of unactivated alkenes. A β-amino alcohol was employed as the ligand for non-asymmetric 1,2-borylalkylation of unactivated alkenes, while a bulky chiral diamine ligand was used to achieve the asymmetric 1,2-borylalkylation of allyl amides.
View Article and Find Full Text PDFSynthesis of Amphiphilic Cationic Poly(β-amino acid) Derivatives and Their PEG Length Optimization for mRNA Transfection.
Biomacromolecules
January 2025
Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea.
We synthesized a series of amphiphilic cationic poly(ethylene glycol)--poly(β-amino acid) derivatives with various lengths of PEG to investigate the effects of PEG lengths on mRNA transfection. The surface charges of the polyplexes with a DP ≥ 4 gradually decreased as DP increased. This indicated that hydrophilic PEG with a DP ≥ 4 was exposed on the surface of the polyplexes, which was further confirmed using H NMR.
View Article and Find Full Text PDFPolysubstituted Pyridines from 1,4-Oxazinone Precursors.
J Org Chem
December 2024
Department of Chemistry, William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States.
This study describes a general method for the preparation of 1,4-oxazin-2-one intermediates from acetylene dicarboxylate and β-amino alcohol precursors. Oxazinones prepared in this manner were employed in a tandem cycloaddition/cycloreversion reaction sequence with a model alkyne (phenyl acetylene) to give substituted pyridine products. Fundamental reactivity and selectivity studies are complemented by the synthesis of the polycyclic ergot alkaloid natural product xylanigripone A.
View Article and Find Full Text PDFCyclic carbamates based on (R)-(+)-limonene oxide for ring-opening polymerization.
Sci Rep
October 2024
Department of Chemistry, Materials, and Chemical Engineering "G. Natta", Politecnico di Milano, via Mancinelli 7, 20131, Milan, Italy.
Article Synopsis
- A new method for creating polyurethanes without isocyanates is introduced, using β-amino alcohols synthesized from (R)-(+)-limonene oxide and primary amines in hot water.
- The research explores the selectivity of these reactions through computational studies, particularly focusing on the role of water and the nucleophile in determining reaction outcomes.
- Cyclic carbamates are formed from the β-amino alcohols, leading to an oligourethane via Anionic Ring-Opening Polymerization, with thorough characterization performed using H and C NMR spectroscopies.
Want 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!