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Henri Doucet - One of the best experts on this subject based on the ideXlab platform.
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late stage pd catalyzed c h bond functionalization a powerful tool for the one step access to arylated cyproheptadine and cyclobenzaprine derivatives
Catalysis Communications, 2019Co-Authors: Dhieb Atoui, Ridha Ben Salem, Thierry Roisnel, Elsa Caytan, Jean-françois Soulé, Haoran Li, Henri DoucetAbstract:Abstract The reactivity of Cyproheptadine and Cyclobenzaprine in Pd-catalyzed arylation via C-H bond functionalizations was investigated. From Cyproheptadine using aryl Bromides as aryl sources and 5 mol% of a palladium catalyst, the C10-arylated Cyproheptadine derivatives were regioselectively obtained. The highest yields were obtained with electron-rich aryl Bromides, but the reaction tolerated useful functional groups on the aryl bromide such as dimethylamino, methoxy, hydroxyl, alkyl, aryl, fluoro, chloro and trifluoromethyl. Cyclobenzaprine was also reactive under the same reaction conditions. © 2019 Elsevier Science. All rights reserved.
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Palladium-Catalyzed Regioselective Direct Arylation of Benzofurazans at the C-4 Position
Advanced Synthesis and Catalysis, 2017Co-Authors: Imane Idris, Jean-françois Soulé, Fazia Derridj, Henri DoucetAbstract:The palladium-catalyzed direct arylation of benzofurazans with aryl Bromides to access 4-ary-lbenzofurazans proceeds in moderate-to-high yields using phosphine-free palladium acetate as the catalyst and potassium acetate as an inexpensive base. A wide variety of (hetero) aryl Bromides, including bromopyridine and bromothiophene derivatives has been successfully employed. Palladium-catalyzed one-pot C-4, C-7-diarylation of benzofurazan was also achieved using a larger amount of aryl bromide. Moreover, the derivatization of 4-arylbenzofurazans into 4-arylquinaxolines is also reported.
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One pot Pd(OAc)2-catalysed 2,5-diarylation of imidazoles derivatives
Tetrahedron, 2014Co-Authors: Abdelilah Takfaoui, Jean-françois Soulé, Liqin Zhao, Rachid Touzani, Pierre H. Dixneuf, Henri DoucetAbstract:The regioselective 2- or 5-arylation of imidazole derivatives with aryl halides using palladium catalysts has been described in recent years; whereas the arylation at both C2 and C5 carbons of imidazoles in high yields has not been performed. We found conditions allowing the access to these 2,5-diarylimidazoles via a one pot reaction. The choice of the base was found to be crucial to obtain these products in high yields. Using CsOAc as the base, DMA as the solvent and only 2 mol % of the phosphine-free Pd(OAc)2 the catalyst, the target 2,5-diarylated imidazoles were obtained in moderate to good yields with a wide variety of aryl Bromides. Substituents such as fluoro, trifluoromethyl, formyl, acetyl, propionyl, ester, nitro or nitrile on the aryl bromide were tolerated. Sterically congested aryl Bromides or heteroaryl Bromides can also be employed. Surprisingly the nature of the substituent at position 1 on the imidazole derivative exhibits a huge influence on the reaction.
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Pd-Catalysed Direct 5-Arylation of 1-Methylpyrazole with Aryl Bromides
SYNTHESIS, 2011Co-Authors: Anissa Beladhria, Kassem Beydoun, Hamed Ben Ammar, Ridha Ben Salem, Henri DoucetAbstract:1-Methylpyrazole was found to be a suitable partner for palladium-catalysed direct arylation through C-H activation/functionalisation using aryl Bromides. The reaction conditions and the nature of the catalyst were found to have a determining influence on the selectivity. The use of an excess of pyrazole (4 equiv), and only 0.5-1 mol% palladium(II) acetate as the catalyst, potassium acetate as the base and DMAc as the solvent, promotes the 5-arylation in moderate to high selectivities and yields. A wide variety of aryl and heteroaryl bromide derivatives have been successfully employed. Their electronic and steric properties also have an influence on the regioselectivities and yields of the coupling products. Both electron-poor and electron-rich aryl Bromides gave satisfactory results, although, very congested products were obtained with lower regioselectivities.
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Palladium catalysed direct 5-arylation of furfurylamine or 2-(aminoalkyl)thiophene derivatives
European Journal of Organic Chemistry, 2010Co-Authors: Julien Roger, Henri DoucetAbstract:The palladium-catalysed direct 5-arylation of furan or thiophene derivatives bearing CH2NHR substituents (with R = COMe or CO2tBu) generally proceeds in good yields by using a catalysts loading of only 0.1-2 mol-%. A wide range of functions such as acetyl, propionyl, formyl, ester, nitrile, trifluoromethyl or fluoro on the aryl bromide is tolerated. Higher yields were generally obtained in the presence of electron-deficient aryl Bromides than with electron-rich aryl Bromides.
Zhiqiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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palladium phosphinous acid complexes catalyzed suzuki cross coupling reaction of heteroaryl Bromides with phenylboronic acid in water alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
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Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid in water/alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
Ben Li - One of the best experts on this subject based on the ideXlab platform.
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palladium phosphinous acid complexes catalyzed suzuki cross coupling reaction of heteroaryl Bromides with phenylboronic acid in water alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
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Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid in water/alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
Cuiping Wang - One of the best experts on this subject based on the ideXlab platform.
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palladium phosphinous acid complexes catalyzed suzuki cross coupling reaction of heteroaryl Bromides with phenylboronic acid in water alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
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Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid in water/alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
Guang Chen - One of the best experts on this subject based on the ideXlab platform.
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palladium phosphinous acid complexes catalyzed suzuki cross coupling reaction of heteroaryl Bromides with phenylboronic acid in water alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
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Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid in water/alcoholic solvents
Journal of Environmental Sciences-china, 2013Co-Authors: Ben Li, Cuiping Wang, Guang Chen, Zhiqiang ZhangAbstract:Abstract Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl Bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl Bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh 3 ) 4 and Pd 2 (dba) 3 . The mechanism of Suzuki cross-coupling reaction between heteroaryl Bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.
