636 research outputs found
Synthesis and biological evaluation of novel 2,3-dihydro-1H-1,5-benzodiazepin-2-ones; potential imaging agents of the metabotropic glutamate 2 receptor
A focused library of novel 2,3-dihydro-1H-1,5-benzodiazepin-2-ones containing sites for 11C-, 18F- and 123I-labelling have been prepared and evaluated against membrane expressing human recombinant metabotropic glutamate 2 receptor (mGluR2). The compounds were found to be non-competitive antagonists with nanomolar affinity. HPLC evaluation of the physiochemical properties of these compounds identified two candidates for PET and SPECT imaging of mGluR2
Activation of Pyridinium Salts for Electrophilic Acylation: a Method for Conversion of Pyridines into 3-Acylpyridines
Cyanide adducts of N-MOM pyridinium salts react with strong acylating reagents to provide 3-acyl-4-cyano-1,4-dihydropyridines that can be aromatized to 3-acylpyridines using ZnCl 2 in refluxing ethanol.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41517/1/10593_2004_Article_496956.pd
Metal-free electrochemical synthesis of sulfonamides directly from (hetero)arenes, SO2, and amines
Sulfonamides are among the most important chemical motifs in pharmaceuticals and agrochemicals. However, there is no methodology to directly introduce the sulfonamide group to a non-prefunctionalized aromatic compound. Herein, we present the first dehydrogenative electrochemical sulfonamide synthesis protocol by exploiting the inherent reactivity of (hetero)arenes in a highly convergent reaction with SO2 and amines via amidosulfinate intermediate. The amidosulfinate serves a dual role as reactant and supporting electrolyte. Direct anodic oxidation of the aromatic compound triggers the reaction, followed by nucleophilic attack of the amidosulfinate. Boron-doped diamond (BDD) electrodes and a HFIPâMeCN solvent mixture enable selective formation of the sulfonamides. In total, 36â
examples are demonstrated with yields up to 85â%
3,5-Bis(trifluoromethyl)iodobenzene
InChIâ=â1S/C8H3F6I/c9-7(10,11)4-1-5(8(12,13)14)3-6(15)2-4/h1-3H
InChIKeyâ=âVDPIZIZDKPFXLI-UHFFFAOYSA-N
(reagent used as a versatile allylation or arylation component)
Physical Data:âbp 59â61â°C (10 mmHg); fp 74â°C; d 1.919 g cm^(â3).
Solubility:âsol DMF, acetonitrile, toluene, and most organic solvents.
Form Supplied in:âpale pink liquid; commercially available.
Purification:âdried over MgSO_4 and fractionally distilled under vacuum.
Handling, Storage, and Precautions:âair, light, and moisture sensitive; to be handled in an inert atmosphere; stored in cool, dark, and dry conditions and away from oxidizing agents
Catalyst-Controlled Chemoselective Arylation of 2-Aminobenzimidazoles
What N would you like? The chemoselective and complementary Pd- and Cu-catalyzed N-arylation of 2-aminobenzimidazoles is described. Selective N-arylation of the amino group was achieved with a Pd-catalyzed method, while selective N-arylation of azole nitrogen was achieved with a Cu-catalyzed procedure (see scheme).National Institutes of Health (U.S.) (GM58160
Origins of High Catalyst Loading in Copper(I)-Catalysed Ullmann- Goldberg C-N Coupling Reactions
Mechanistic investigation of Ullmann-Golberg reactions using soluble and partially soluble bases led to identification of various pathways for catalyst deactivation through (i) product inhibition with amine products, (ii) byproduct inhibition with inorganic halide salts, and (iii) ligand exchange by soluble carboxylate bases. Reactions using a partially soluble inorganic bases showed variable induction periods, which is responsible for reproducibility issues in these reactons. Surprisingly, more finely milled Cs2CO3 resulted in longer induction period due to higher concentration of deprotonated amine/amide, leading to suppressed catalytic activity. These results have singificant implications on future ligand development for Ullmann-Goldberg reaction, and on the solid form of the inorganic bases as an important variable with mechanistic ramifications in many catalytic reactions
Origins of High Catalyst Loading in Copper(I)-Catalysed Ullmann- Goldberg C-N Coupling Reactions
Mechanistic investigation of Ullmann-Golberg reactions using soluble and partially soluble bases led to identification of various pathways for catalyst deactivation through (i) product inhibition with amine products, (ii) byproduct inhibition with inorganic halide salts, and (iii) ligand exchange by soluble carboxylate bases. Reactions using a partially soluble inorganic bases showed variable induction periods, which is responsible for reproducibility issues in these reactons. Surprisingly, more finely milled Cs2CO3 resulted in longer induction period due to higher concentration of deprotonated amine/amide, leading to suppressed catalytic activity. These results have singificant implications on future ligand development for Ullmann-Goldberg reaction, and on the solid form of the inorganic bases as an important variable with mechanistic ramifications in many catalytic reactions
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