نتایج جستجو برای: propargylamines
تعداد نتایج: 106 فیلتر نتایج به سال:
Highly active Cu (II) complex with 1,4-dihydroxy anthraquinone as a cheap and accessable ligand could be used as a catalyst for the preparation of structurally different propargylamines from a one-pot, three-component reaction of terminal alkynes, aldehydes, and secondary amines with high yields under solvent-free conditions. The 1,4-dihydroxy anthraquinone is a very efficient Cu(II) scavenger ...
During this study, we report the green synthesis of silver nanoparticles (Ag NPs) using Euphorbia helioscopia Linn leaf extract for the synthesis of propargylamines. Also, the structural and optical properties are studied. The synthesized nanoparticles are characterized by TEM, XRD, FT-IR and UV-visible techniques. UV-visible studies show an absorption band at 440 nm due to surface plasmon reso...
A variety of substituted chiral propargylamines have been synthesized by reacting chiral N-phosphonylimines with lithium aryl/alkyl acetylides. Seventeen examples were studied to give excellent yields (>90%) and diastereoselectivities (96 : 4 to 99 : 1). It was found that the types of bases for generating acetylides and solvents are crucial for effectiveness of this asymmetric reaction. In addi...
highly active cu (ii) complex with 1,4-dihydroxy anthraquinone as a cheap and accessable ligand could be used as a catalyst for the preparation of structurally different propargylamines from a one-pot, three-component reaction of terminal alkynes, aldehydes, and secondary amines with high yields under solvent-free conditions. the 1,4-dihydroxy anthraquinone is a very efficient cu(ii) scavenger ...
[reaction: see text] A regioselective synthesis of propargylamines by the coupling of propargyl alcohols with tosylamines and carbamates catalyzed by an air- and moisture-tolerant rhenium-oxo complex is described. The ability to couple functionalized components allows for convergent approaches to nitrogen-containing heterocyclic compounds such as the marine antibiotic pentabromopseudilin. These...
Cationic gold-catalyzed cycloisomerizations of propargylureas, derived in situ from secondary propargylamines and aryl or alkyl isocyanates, have been studied. The reaction outcome was found to be different from what was previously observed for the tosyl isocyanate-derived ureas in terms of both regio- and chemoselectivity. As a result, the current protocol offers efficient access to the 3,4-di...
A novel and efficient decarboxylative alkynylation of N-(acetoxy)phthalimides of α-amino acids with terminal alkynes has been developed by merging photoredox with copper catalysis at room temperature, and the reaction provided the valuable propargylamines in good to excellent yields with assistance of [Ru(bpy)3]Cl2/CuI and visible light. The simple protocol, mild reaction conditions, and high e...
We report herein a CuBr-catalyzed three-component coupling of 2-methylbut-3-yn-2-ol, aldehydes and pyrrolidine or 1,2,3,4-tetrahydroisoquinoline leading to the corresponding chiral propargylamines in excellent enantiomeric excess (91 to >99% ee) and high yields (79-95% yield). The dimethylcarbinol unit in 2-methylbut-3-yn-2-ol, which may be easily removed at the later stage to regenerate a term...
Propargylamines can be obtained from secondary amines and terminal alkynes in chlorinated solvents by a three- and two-component synthesis catalyzed by gold compounds and nanoparticles (Au-NP) under mild conditions. The use of dichloromethane allows for the activation of two C-Cl bonds and a clean transfer of the methylene fragment to the final product. The scope of the reaction as well as the ...
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