55317-39-0

Upstream product

• 288-13-1 NH-pyrazole 
• 342-24-5 o-fluorobenzophenone 
• 1126-00-7 1-phenylpyrazole 
• 100-47-0 benzonitrile 
• 925-90-6 ethylmagnesium bromide 
• 98-88-4 benzoyl chloride 
• 103-50-4 dibenzyl ether 
• 108-88-3 toluene 
• 100-51-6 benzyl alcohol 
• 591-50-4 iodobenzene 
• 74542-54-4 N,N-phenyl-p-toluenesulfonylbenzamide 
• 100-42-5 styrene 

Downstream Products

• 72419-06-8 4-phenyl-4H-pyrazolo[1,5-a]indol-4-ol 
• 1020045-42-4 α-phenyl-(2-(1H-pyrazol-1-yl))benzyl alcohol 

Relevant academic research and scientific papers

Nickel-catalyzed regioselective C-H acylation of chelating arenes: A new catalytic system for C-C bond formation: Via a radical process and its mechanistic explorations

An unprecedented acylation at the ortho C-H bond of chelating arenes via the Ni(ii)-catalyzed cross dehydrogenative coupling strategy has been developed here. This new procedure exhibits excellent regioselectivity and good functional group tolerance. This discovery could be of great importance for the C-H acylation reactions of chelating arenes without any extraneous directing group and for the application of nickel-catalyzed C-H activation. Mechanistic investigations into the reaction process are also described.

Monodisperse CuPd alloy nanoparticles as efficient and reusable catalyst for the C (sp2)–H bond activation

Metal-catalyzed selective activation of C–H bonds is very important for the construction of a variety of biologically active molecules. Supported alloy nanoparticles are of great interest in various catalytic applications due to the synergistic effects between different metals. Here, well-dispersed CuPd alloy nanoparticles supported on reduced graphene oxide (rGO) were synthesized and found to be highly efficient and recyclable catalyst for the chelation-assisted C (sp2)–H bond activation. Aromatic ketones or esters were synthesized via the cross-dehydrogenative coupling (CDC) reaction between 2-arylpyridines and alcohols or acids. Moreover, the catalyst was recovered and used for five times without significantly losing activity.

A Strategy for Amide C-N Bond Activation with Ruthenium Catalyst: Selective Aromatic Acylation

A strategy for amide C-N bond activation with ruthenium catalyst is described for the first time. The in situ formed bis-cycloruthenated complexes were demonstrated to be the key active species with superior oxidative addition ability to an inert amide C-N bond. The direct C-H bond activation of 2-arylpyridines followed by the amide C-N bond activation took place in the presence of a ruthenium precatalyst to produce monoacylation products in moderate to good yields. Synthetically useful functional groups, such as halogen atoms (F and Cl), ester, acetyl, and vinyl, remained intact during tandem C-H/C-N bond activation reactions.

Palladium-catalyzed decarboxylative, decarbonylative and dehydrogenative C(sp2)-H acylation at room temperature

Over the past few decades, an impressive array of C-H activation methodology has been developed for organic synthesis. However, due to the inherent inertness of the C-H bonds (e.g. ～110 kcal mol-1 for the cleavage of C(aryl)-H bonds) harsh reaction conditions have been realized to overcome high energetic transition states resulting in a limited substrate scope and functional group tolerance. Therefore, the development of mild C-H functionalization protocols is in high demand to exploit the full potential of the C-H activation strategy in the synthesis of a complex molecular framework. Although, electron-rich substrates undergo electrophilic metalation under relatively mild conditions, electron-deficient substrates proceed through a rate-limiting C-H insertion under forcing conditions at high temperature. In addition, a stoichiometric amount of toxic silver salt is frequently used in palladium catalysis to facilitate the C-H activation process which is not acceptable from the environmental and industrial standpoint. We report herein, a Pd(ii)-catalyzed decarboxylative C-H acylation of 2-arylpyridines with α-ketocarboxylic acids under mild conditions. The present protocol does not require stoichiometric silver(i) salts as additives and proceeds smoothly at ambient temperature. A novel decarbonylative C-H acylation reaction has also been accomplished using aryl glyoxals as acyl surrogates. Finally, a practical C-H acylation via a dehydrogenative pathway has been demonstrated using commercially available benzaldehydes and aqueous hydroperoxides. We also disclose that acetonitrile solvent is optimal for the acylation reaction at room temperature and has a prominent role in the reaction outcome. Control experiments suggest that the acylation reaction via decarboxylative, decarbonylative and dehydrogenative proceeds through a radical pathway. Thus we disclose a practical protocol for the sp2 C-H acylation reaction.

Polystyrene supported Dichloro-(8-aminoquinoline)-Palladium(II) complex catalyzed C[sbnd]H bond activation for ortho-acylation of 2-aryl pyridines

Polystyrene-supported Dichloro-(8-aminoquinoline)-Pd(II) complex C was synthesized and its catalytic efficiency was evaluated for ortho-acylation of 2-aryl pyridines with alcohols to form aryl ketones via cross dehydrogenative coupling. In addition in the presence of Pd(II) complex, toluene derivatives were also employed as an effective coupling partner for synthesis of aromatic ketones. Furthermore, this catalyst was highly stable and could be easily recovered by simple filtration and reused for four cycles with no significant decrease in its activity and selectivity.

Replacing Pd(OAc)2 with supported palladium nanoparticles in ortho-directed CDC reactions of alkylbenzenes

Supported palladium nanoparticles are used as efficient catalysts for the synthesis of aromatic ketones via cross dehydrogenative coupling reactions of 2-arylpyridines with alkylbenzenes. The catalyst can be reused for five cycles without significantly losing activity. Mechanism research showed that alkylbenzenes were oxidized to their corresponding aldehydes and subsequently coupled with 2-arylpyridines to generate aryl ketones through a Pd0/PdII/PdIV catalytic cycle.

Palladium-catalyzed oxidative synthesis of aromatic ketones using olefins as acyl equivalents through selective ortho aromatic C-H bond activation

An efficient catalytic system has been developed for selective ortho-acylation of arenes by oxidative C-H bond activation using a palladium catalyst. Olefins were oxidized to the corresponding aldehydes/benzoyl radicals, which, on coupling with 2-phenylpy

Pd-catalyzed oxidative coupling of arene C-H bonds with benzylic ethers as acyl equivalents

A palladium-catalyzed oxidative coupling of arene C-H bonds with benzylic ethers via C-H bond activation is described. The reaction proceeds efficiently with a broad range of substrates bearing conventional directing groups with excellent functional group compatibility. This protocol potentially provides opportunities to use dibenzyl ethers as new acyl equivalents for catalytic acylation reactions.

Ruthenium-catalyzed C-H functionalization of arylpyrazoles: Regioselective acylation with acid chlorides

A ruthenium-catalyzed C-H acylation of arylpyrazoles with a variety of acyl chlorides is described. The acylation reaction exhibits good regioselectivity and both aromatic and aliphatic acyl chlorides can be effectively coupled to the arylpyrazoles at the

Rh-catalyzed C-C cleavage of benzyl/allylic alcohols to produce benzyl/allylic amines or other alcohols by nucleophilic addition of intermediate rhodacycles to aldehydes and imines

We report three transformations: 1) direct transformation from biarylmethanols into biarylmethylamines; 2) direct transformation from one biarylmethanol into another biarylmethanol; 3) direct transformation from allylic alcohols into allylic amines. These transformations are based on pyridyl-directed Rh-catalyzed C-C bond cleavage of secondary alcohols and subsequent addition to C=X (X=N or O) double bonds. The reaction conditions are simple and no additive is required. The driving force of C-C bond cleavage is the formation of the stable rhodacycle intermediate. Other directing groups, such as the pyrazolyl group, can also be used although it is not as efficient as the pyridyl group. We carried out in-depth investigations for transformation 1 and found that: 1) the substrate scope was broad and electron-rich alcohols and electron-deficient imines are more efficient; 2) as the leaving group, aldehyde had no significant impact on either the C-C bond cleavage or the whole transformation; 3) mechanistic studies (intermediate isolation, in situ NMR spectroscopic studies, competing reactions, isotopic labeling experiments) implied that: i) The C-C cleavage was very efficient under these conditions; ii) there is an equilibrium between the rhodacycle intermediate and the protonated byproduct phenylpyridine; iii) the addition step of the rhodacycle intermediate to imines was slower than the C-C cleavage and the equilibrium between the rhodacycle and phenylpyridine; iv) the whole transformation was a combination of two sequences of C-C cleavage/nucleophilic addition and C-C cleavage/protonation/C-H activation/nucleophilic addition, with the latter being perhaps the main pathway. We also demonstrated the first example of cleavage of an C(alkenyl)-C(benzyl) bond. These transformations showed the exchange (or substitution) of the alcohol group with either an amine or another alcohol group. Like the "group transplant", this method offers a new concept that can be used to directly synthesize the desired products from other chemicals through reorganization of carbon skeletons.