20157-45-3

Upstream product

• 1453-58-3 3-Methylpyrazole 
• 92070-54-7 3-methyl-1-p-tolyl-4,5-dihydropyrazole 
• 106-49-0 p-toluidine 
• 352-32-9 p-fluorotoluene 
• 637-60-5 p-tolylhydrazine hydrochloride 
• 29540-83-8 p-tolyl triflate 
• 106-43-4 para-chlorotoluene 

Relevant academic research and scientific papers

TBHP/Cu(OAc)2 mediated oxidation of pyrazolines: A convenient method for the preparation of pyrazoles

An efficient and simple oxidative protocol has been developed for the preparation of pyrazoles from pyrazolines mediated by TBHP/Cu(OAc)2 at room temperature. The present protocol has been successfully applied for the preparation of various pyrazole compounds from heterocyclic pyrazolines.

Nucleophilic aromatic substitution of unactivated fluoroarenes enabled by organic photoredox catalysis

Nucleophilic aromatic substitution (SNAr) is a classical reaction with well-known reactivity toward electron-poor fluoroarenes. However, electron-neutral and electron-rich fluoro(hetero)arenes are considerably underrepresented. Herein, we present a method for the nucleophilic defluorination of unactivated fluoroarenes enabled by cation radical-accelerated nucleophilic aromatic substitution. The use of organic photoredox catalysis renders this method operationally simple under mild conditions and is amenable to various nucleophile classes, including azoles, amines, and carboxylic acids. Select fluorinated heterocycles can be functionalized using this method. In addition, the late-stage functionalization of pharmaceuticals is also presented. Computational studies demonstrate that the site selectivity of the reaction is dictated by arene electronics.

Synthesis of n-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives

A method for the synthesis of N-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C-N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives proceeded efficiently to give N-arylpyrazole products in high yields. 3-Trimethylsilylpyrazole was found to be an excellent pyrazole substrate for the coupling, and the corresponding product, 1-aryl-3-trimethylsilylpyrazole, also served as a great template for the syntheses of N-arylpyrazole derivatives, as demonstrated by regioselective halogenation at the 3-, 4-, and 5-positions of the pyrazole ring.

Synthesis of N-Arylpyrazoles by Palladium-Catalyzed Coupling of Aryl Triflates with Pyrazole Derivatives

A method for the synthesis of N-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C-N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives proceeded efficiently to give N-arylpyrazole products in high yields. 3-Trimethylsilylpyrazole was found to be an excellent pyrazole substrate for the coupling, and the corresponding product, 1-aryl-3-trimethylsilylpyrazole, also served as a great template for the syntheses of N-arylpyrazole derivatives, as demonstrated by regioselective halogenation at the 3-, 4-, and 5-positions of the pyrazole ring.

Water-soluble cyclic palladium hydrate mono-phosphine salt compound, and preparation method and application thereof

The invention relates to a water-soluble cyclic palladium hydrate mono-phosphine salt compound, and a preparation method and an application thereof. The compound has a formula shown in the specification, wherein L is a sulfo group-containing mono-phosphine ligand, a phosphine atom and a palladium coordinate; the hydroxy benzyl groups can be singly or simultaneously located on a pyridine ring and a benzene ring; and the hydroxy benzyl groups can be located on any positions on the two rings. According to the invention, the cyclic palladium dimer containing the hydroxy benzyl groups and the sodium salt of the sulfo group-containing mono-phosphine ligand react with each other in an acetone solvent, so that the corresponding water-soluble cyclic palladium hydrate mono-phosphine salt compound can be conveniently synthesized. When the compound is used as a metal catalyst, the dosage of the catalyst is small; clean water used as the solvent and low-cost weak base can be utilized to effectively catalyze the coupled reaction between aryl halide and pyrazole, so as to synthesize and prepare 1-aryl pyrazole. The method has the advantages that the scope of the reaction substrate is wide, the reaction condition is mild, the yield is high, the method is economical and efficient and the method has an important application value.

Copper-catalyzed arylation of nitrogen heterocycles from anilines under ligand-free conditions

The arylation of pyrazole and derivatives can be achieved by coupling arenediazonium species (formed in situ from anilines) by using a catalytic system that employs low-toxicity and inexpensive copper metal under very mild and ligand-free conditions (T = 20 ° C). From other nitrogen heterocycles, the presence of an additive (NBu4I) significantly improves the efficiency of the catalytic system. These results represent the first examples of C-N bond formation from arenediazonium species.

Zinc-catalyzed synthesis of pyrazolines and pyrazoles via hydrohydrazination

(Chemical Equation Presented) A novel regioselective synthesis of aryl-substituted pyrazolines and pyrazoles has been developed. Substituted phenylhydrazines react with 3-butynol in the presence of a catalytic amount of zinc triflate to give pyrazoline derivatives. The resulting products are easily oxidized in a one-pot procedure to the corresponding pyrazoles.

Hypervalent iodine in synthesis 57 : An efficient method for the synthesis of N-arylimidazoles by the cobalt-catalysed coupling of diaryliodonium salts with imidazoles

Cobalt-catalysed N-arylation of imidazole with diaryliodonium salt can be accomplished using Co(OAC)2 as a catalyst and K2CO3 as a base in DMF at 80 °C in high yields.