The first regio-, diastereo-, and enantioselective allylic alkylation of acyclic β-ketoesters to form vicinal tertiary and all-carbon quaternary stereocenters is reported. Critical to the successful development of this method was the employment of iridium catalysis in concert with N-aryl-phosphoramidite ligands. Broad functional group tolerance is observed at the keto-, ester-, and α-positions of the nucleophile. Various transformations demonstrating the utility of this method for rapidly accessing complex enantioenriched compounds are reported.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3881553 | PMC |
http://dx.doi.org/10.1021/ja4097829 | DOI Listing |
Molecules
January 2025
Université de Reims Champagne-Ardenne, CNRS, ICMR, 51097 Reims, France.
A straightforward synthetic route towards DAB-1 scaffolded dimeric iminosugars is described here, starting from readily available bis-glycosylamines. The method allows the integration of a variety of linkages (aryl, alkyl, polyethyleneglycol chains) between both iminosugars through the choice of the bis-amine used in the first step. Moreover, an additional substituent (allyl, ethynyl) may be inserted into the structure via nucleophilic addition of an organometallic reagent to the starting bis-glycosylamine.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Department of Chemistry, Iowa State University, Ames, IA, 50011, USA. Electronic address:
Background: Infections from the hepatitis B virus (HBV) are a major risk factor for hepatocellular carcinoma, one of the most common types of liver cancer. Circulating cell-free DNA (ccfDNA) in human plasma can be used as a non-invasive biomarker for diagnosing HBV-related liver diseases. The isolation of target ccfDNA sequences is often challenging due to the co-extraction of highly abundant non-target DNA from samples.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.
A novel palladium-catalyzed allylic C-H alkylation of terminal olefins with 3-carboxamide oxindoles is described. A variety of new 3-carboxamide-3-allylation oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%). In addition, the asymmetric version of this reaction was also explored, providing moderate enantioselectivity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
New Cornerstone Science Laboratory, State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, China.
Rhodium-catalyzed regio- and enantioselective allylic arylation of racemic alkyl- and aryl- substituted allylic carbonates with arylboronic acids using commercially available BIBOP ligand is reported. This reaction proceeds at room temperature without base or other additive to deliver allylic arylation products in excellent yields, regio- and enantioselectivity (up to 95 % yield, >20 : 1 b/l, >99 % ee). Rh/BIBOP is disclosed as an efficient catalytic system for allylic substitution reaction.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Applied Organic Chemistry & College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
The cycloaddition of aziridines with unsaturated compounds is a valuable method for synthesizing nitrogen heterocycles. However, this process is predominantly substrate-controlled, posing significant challenges in regulating the regioselectivity of the C-N bond cleavage. In this study, we report a nickel-catalyzed dynamic kinetic activation strategy that enables catalyst-controlled activation of aziridines.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!