Search results for "Condensation reaction"
showing 4 items of 84 documents
On the synthesis of functionalized porphyrins and porphyrin conjugates via β-aminoporphyrins
2016
International audience; The synthesis of functionalized porphyrins and their conjugates from meso-tetraarylporphyrins through the acylation and the oxidation of beta-aminoporphyrins was investigated. 2,3-Dioxochlorins were prepared by the oxidation of a variety of beta-aminoporphyrins and subsequently used in a condensation reaction with functionalized aromatic aldehydes and ammonium acetate to form beta-functionalized porphyrins bearing a fused imidazole ring. Under optimized experimental conditions both reactions tolerate various functional groups and afford the products in an appropriate overall yield. The mildness and usefulness of this methodology are illustrated by several examples in…
Catalytic activity of humic substances in condensation reactions
1998
Abstract Humic substances (HS) have considerable impact on the fate of organic xenobiotics in natural environments. This paper reports on the catalytic activity of HS in condensation reactions of carbonyl compounds with active methylene compounds, using Knoevenagel and Claisen-Schmidt reactions as examples. Of the HS, the aquatic fulvic acids are the most active, but the velocity of condensation reactions depends also on the temperature, concentration and form of HS (free or salt) used, and the solvent.
1,2,6-Thiadiazine 1-Oxides: Unsaturated Three-Dimensional S,N-Heterocycles from Sulfonimidamides.
2020
Unprecedented three-dimensional 1,2,6-thiadiazine 1-oxides have been prepared by an aza-Michael-addition/cyclization/condensation reaction sequence starting from sulfonimidamides and propargyl ketones. The products have been further functionalized by standard cross-coupling reactions, selective bromination of the heterocyclic ring, and conversion into a β-hydroxy substituted derivative. A representative product was characterized by single-crystal X-ray structure analysis. peerReviewed
Synthesis of new hybrid 1,4-thiazinyl-1,2,3-dithiazolyl radicals via Smiles rearrangement
2017
The condensation reaction of 2-aminobenzenethiols and 3-aminopyrazinethiols with 2-amino-6-fluoro-N-methylpyridinium triflate afforded thioether derivatives that were found to undergo Smiles rearrangement and cyclocondensation with sulphur monochloride to yield new hybrid 1,4-thiazine-1,2,3-dithiazolylium cations. The synthesized cations were readily reduced to the corresponding stable neutral radicals with spin densities delocalized over both 1,4-thiazinyl and 1,2,3-dithiazolyl moieties. peerReviewed