A general enantioselective organocatalytic conjugate addition procedure of a variety of malonates to alpha,beta-unsaturated enone systems is presented. The reaction is efficiently catalysed by the pyrrolidinyl tetrazole catalyst 1. Cyclic, acyclic and aromatic enones can be used and the reaction with ethyl malonates 3 b provides the Michael addition products in high yields with good to excellent enantioselectivities. Since only 1.5 equivalents of malonate are used as a reagent, the reaction is readily scaled and practical to operate. Furthermore, the malonate addition products can be easily mono decarboxylated without loss in enantiomeric excess by enzymatic or sodium hydroxide mediated methods.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/chem.200800673 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Nitrate-Photolysis Shortens the Lifetimes of Brown Carbon Tracers from Biomass Burning.
Environ Sci Technol
December 2024
State Ecology and Environment Scientific Observation and Research Station for the Yangtze River Delta at Dianshan Lake, Shanghai Environmental Monitoring Center, Shanghai 200030, China.
Biomass burning is an important source of brown carbon (BrC) aerosols, which influence climate by affecting the Earth's radiative balance. However, the transformation pathways of BrC chromophores, especially in the presence of photochemically active species, such as nitrate, are not well understood. In this study, the nitrate-mediated aqueous-phase photooxidation of three typical BrC chromophores from biomass burning was investigated, including 4-nitrocatechol, 3-nitrosalicylic acid, and 3,4-dinitrophenol.
View Article and Find Full Text PDFEarly Response of the L. × Hybrid to Soil Enrichment with Metals.
Int J Mol Sci
November 2024
Department of Analytical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznan, Poland.
This study aimed to investigate the response of L. × to the addition of selected metals in soil. Rooted cuttings were planted in pots containing soil enriched with equimolar concentrations of Pb, Zn, Al, Ni, and Cu (500 mL of 4 mM solutions of single metal salts: (Pb(NO); Zn(NO) × 6HO; Al(NO) × 9HO; Ni(NO) × 6HO; or Cu(NO) × 3HO).
View Article and Find Full Text PDFThe effects of age and sex on reference intervals for cobalamin, homocysteine, and serum and urinary methylmalonic acid in healthy adult dogs.
J Vet Intern Med
December 2024
Clinic for Small Animals, Internal Medicine, JLU Giessen, Frankfurter Strasse 114, Giessen 35392, Germany.
Background: In dogs, data on reference intervals (RIs) for cobalamin, markers of metabolism (markersBmet), age and sex effects are limited.
Hypothesis/objectives: Establish RI for serum cobalamin, homocysteine, and methylmalonic acid (sMMA) concentrations, urinary methylmalonic acid-to-creatinine ratio (uMMA:crea), and determine effects of sex and age.
Methods: Prospective study using healthy dogs (1-10 years).
The Impact of Green Tea Kombucha on the Intestinal Health, Gut Microbiota, and Serum Metabolome of Individuals with Excess Body Weight in a Weight Loss Intervention: A Randomized Controlled Trial.
Foods
November 2024
Department of Nutrition and Health, Universidade Federal de Viçosa, Viçosa 36570-900, Brazil.
Green tea kombucha (GTK) has emerged as a promising probiotic fermented beverage. Few studies have investigated its effect on human health, mainly focusing on intestinal health, microbiota composition, and metabolomics. The present study is a pioneer in investigating the effect of GTK consumption in individuals with excess body weight.
View Article and Find Full Text PDFMultimodal analysis identifies microbiome changes linked to stem cell transplantation-associated diseases.
Microbiome
November 2024
Fundación Para El Fomento de La Investigación Sanitaria y Biomédica de La Comunitat Valenciana-FISABIO, Valencia, Spain.
Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most efficient therapeutic options available to cure many hematological malignancies. However, severe complications derived from this procedure, including graft-versus-host disease (GVHD) and infections, can limit its success and negatively impact survival. Previous studies have shown that alterations in the microbiome are associated with the development of allo-HSCT-derived complications.
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!