scholarly journals Hindered aryl bromides for regioselective palladium-catalysed direct arylation at less favourable C5-carbon of 3-substituted thiophenes

2014 ◽  
Vol 10 ◽  
pp. 1239-1245 ◽  
Author(s):  
Rongwei Jin ◽  
Charles Beromeo Bheeter ◽  
Henri Doucet
Keyword(s):  
Palladium Catalyst ◽  
Thiophene Ring ◽  
Aryl Bromide ◽  
Direct Arylation ◽  
Bond Functionalization ◽  
Aryl Bromides ◽  
Thiophene Derivatives ◽  
Coupling Partner

The use of the congested aryl bromide 2-bromo-1,3-dichlorobenzene as coupling partner allows to modify the regioselectivity of the arylation of 3-substituted thiophene derivatives in favour of carbon C5. The coupling of this aryl bromide with a variety of 3-substituted thiophenes gave in all cases the desired 5-arylation products in moderate to good yields using only 0.5 mol % of a phosphine-free and air-stable palladium catalyst. Then, from these 5-arylthiophenes, a second palladium-catalysed C–H bond functionalization at C2 of the thiophene ring allows the synthesis of 2,5-diarylthiophenes with two different aryl units.

Synthesis of conjugated polymers using aryl-bromides via Cu-catalyzed direct arylation polymerization (Cu-DArP)

2019 ◽  
Vol 10 (48) ◽  
pp. 6545-6550 ◽  
Author(s):  
Liwei Ye ◽  
Robert M. Pankow ◽  
Alexander Schmitt ◽  
Barry C. Thompson
Keyword(s):  
Conjugated Polymers ◽  
Copper Catalysts ◽  
Aryl Bromide ◽  
Direct Arylation ◽  
First Report ◽  
Aryl Bromides ◽  
Direct Arylation Polymerization

The first report on direct arylation polymerization with copper catalysts and aryl-bromide monomers expands the sustainability and practicality of DArP.

scholarly journals Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

2019 ◽  
Vol 15 ◽  
pp. 2069-2075 ◽  
Author(s):  
Hai-Yun Huang ◽  
Haoran Li ◽  
Thierry Roisnel ◽  
Jean-François Soulé ◽  
Henri Doucet
Keyword(s):  
Nitrogen Atom ◽  
Biological Properties ◽  
Quinoline Derivatives ◽  
Aryl Bromide ◽  
One Pot ◽  
Bond Functionalization ◽  
Aryl Bromides ◽  
The One

The Pd-catalyzed C–H bond functionalization of lilolidine was investigated. The use of a palladium-diphosphine catalyst associated to acetate bases in DMA was found to promote the regioselective arylation at α-position of the nitrogen atom of lilolidine with a wide variety of aryl bromides. From these α-arylated lilolidines, a second arylation at the β-position gives the access to α,β-diarylated lilolidines containing two different aryl groups. The one pot access to α,β-diarylated lilolidines with two identical aryl groups is also possible by using a larger amount of aryl bromide. The synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles from lilolidine via three successive direct arylations is also described. Therefore, this methodology provides a straightforward access to several lilolidine derivatives from commercially available compounds via one, two or three C–H bond functionalization steps allowing to tune their biological properties.

scholarly journals Regiocontroled Pd-catalysed C5-arylation of 3-substituted thiophene derivatives using a bromo-substituent as blocking group

2016 ◽  
Vol 12 ◽  
pp. 2197-2203 ◽  
Author(s):  
Mariem Brahim ◽  
Hamed Ben Ammar ◽  
Jean-François Soulé ◽  
Henri Doucet
Keyword(s):  
Suzuki Coupling ◽  
Pd Catalyst ◽  
Direct Arylation ◽  
Blocking Group ◽  
Aryl Bromides ◽  
Thiophene Derivatives ◽  
High Yields

The use of a bromo-substituent as blocking group at the C2-position of 3-substituted thiophenes allows the regioselective introduction of aryl substituents at C5-position via Pd-catalysed direct arylation. With 1 mol % of a phosphine-free Pd catalyst, KOAc as the base and DMA as the solvent and various electron-deficient aryl bromides as aryl sources, C5-(hetero)arylated thiophenes were synthesized in moderate to high yields, without cleavage of the thienyl C–Br bond. Moreover, sequential direct thienyl C5-arylation followed by Pd-catalysed direct arylation or Suzuki coupling at the C2-position allows to prepare 2,5-di(hetero)arylated thiophenes bearing two different (hetero)aryl units in only two steps. This method provides a “green” access to arylated thiophene derivatives as it reduces the number of steps to prepare these compounds and also the formation of wastes.

C−H Arylation of Thiophenes with Aryl Bromides by a Parts-per-Million Loading of a Palladium NNC-Pincer Complex

Synlett ◽  
2020 ◽  
Vol 31 (16) ◽  
pp. 1634-1638
Author(s):  
Yasuhiro Uozumi ◽  
Anggi Eka Purta ◽  
Shun Ichii ◽  
Aya Tazawa
Keyword(s):  
Pivalic Acid ◽  
Efficient Synthesis ◽  
Direct Arylation ◽  
Pincer Complex ◽  
Aryl Bromides ◽  
Thiophene Derivatives

A palladium NNC-pincer complex efficiently catalyzed the direct arylation of thiophene derivatives with extremely low palladium loadings of the order of parts per million. Thus, the reaction of various thiophenes with aryl bromides in the presence of 25–100 mol ppm of chlorido[(2-phenyl-κ-C 2)-9-phenyl-1,10-phenanthroline-κ2-N,N′]palladium(II) NNC-pincer complex, K2CO3, and pivalic acid in N,N-dimethyl­acetamide afforded the corresponding 2- or 5-arylated thiophenes in good to excellent yields. A combination of the present C–H arylation and Hiyama coupling with the same NNC-pincer complex provides an efficient synthesis of unsymmetrical 2,5-thiophenes with catalyst loadings at mol ppm levels.

scholarly journals HIGHLY EFFICIENT SYNTHESIS OF 2,4-DISUBSTITUTED OXAZOLES THROUGH PALLADIUM/COPPER COMEDIATED DIRECT ARYLATION REACTION

2018 ◽  
Vol 11 (8) ◽  
pp. 511
Author(s):  
Venkata Reddy Regalla ◽  
Rama Krishnam Raju Addada ◽  
Venkat Swamy Puli ◽  
Abhishek S Saxena ◽  
Anindita Chatterjee
Keyword(s):  
Fourier Transform ◽  
13C Nmr ◽  
Functional Group ◽  
Combinatorial Synthesis ◽  
Spectral Studies ◽  
Aryl Bromide ◽  
Efficient Synthesis ◽  
Direct Arylation ◽  
Mass Spectral ◽  
Aryl Bromides

Objective: The aim of the present study is to synthesize 2,4-disubstituted oxazoles through palladium/copper comediated direct arylation reaction.Methods: 2,4-disubstituted oxazoles (3a-i) have been synthesized by the reaction of 4-substituted oxazole with aryl bromide in the presence of KOH , CuI and Pd(PPh3)4 in dimethoxyethane. Titled compounds (3a-i) were obtained in good yields using an expedient two-step synthesis of 2,4-disubstituted oxazoles from commercially available starting materialsResults: The structures of the newly synthesized compounds were characterized by Fourier-transform infrared, 1H NMR, 13C NMR, and mass spectral studies. This method can be an efficient method for the synthesis of 2,4-disubstituted oxazoles (3a-i).Conclusion: Pd(PPh3)4 and CuI cocatalytic system direct arylation of 4-aryl/alkyl oxazoles with various aryl bromides has been developed to generate 2,4-disubstituted oxazoles. The high functional group tolerance and the speed of the reaction afford this method appropriate for the combinatorial synthesis of a variety of 2,4-disubstituted oxazoles.

Rh(III)-Catalyzed Olefination and Alkylation of Arenes with Maleimides: A Tunable Strategy for C(sp2)–H Functionalization

Synthesis ◽  
2021 ◽  
Author(s):  
Hongji Li ◽  
Wenjie Zhang ◽  
Xueyan Liu ◽  
Zhenfeng Tian
Keyword(s):  
Room Temperature ◽  
Functional Group ◽  
Reaction Conditions ◽  
Bond Functionalization ◽  
Alkylation Process ◽  
Coupling Partner

AbstractWe herein report a new nitrogen-directed Rh(III)-catalyzed C(sp2)–H bond functionalization of N-nitrosoanilines and azoxybenzenes with maleimides as a coupling partner, in which the olefination/alkylation process can be finely controlled at room temperature by variation of the reaction conditions. This method shows excellent functional group tolerance, and presents a mild access to the resulting olefination/alkylation products in moderate to good yields.

scholarly journals Some chalcones derived from thiophene-3-carbaldehyde: synthesis and crystal structures

2019 ◽  
Vol 75 (7) ◽  
pp. 957-963 ◽  
Author(s):  
Trung Vu Quoc ◽  
Duong Tran Thi Thuy ◽  
Thuan Dang Thanh ◽  
Thanh Phung Ngoc ◽  
Vuong Nguyen Thien ◽  
...  
Keyword(s):  
Potassium Hydroxide ◽  
Thiophene Ring ◽  
Three Dimensional ◽  
Ethanol Solution ◽  
Molecular Structures ◽  
Chain Formation ◽  
Axis Direction ◽  
Crystal And Molecular Structures ◽  
Phenyl Rings ◽  
Thiophene Derivatives

The synthesis, spectroscopic data and crystal and molecular structures of four 3-(3-phenylprop-1-ene-3-one-1-yl)thiophene derivatives, namely 1-(4-hydroxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H10O2S, (1), 1-(4-methoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C14H12O2S, (2), 1-(4-ethoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C15H14O2S, (3), and 1-(4-bromophenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H9BrOS, (4), are described. The four chalcones have been synthesized by reaction of thiophene-3-carbaldehyde with an acetophenone derivative in an absolute ethanol solution containing potassium hydroxide, and differ in the substituent at the para position of the phenyl ring: –OH for 1, –OCH3 for 2, –OCH2CH3 for 3 and –Br for 4. The thiophene ring in 4 was found to be disordered over two orientations with occupancies 0.702 (4) and 0.298 (4). The configuration about the C=C bond is E. The thiophene and phenyl rings are inclined by 4.73 (12) for 1, 12.36 (11) for 2, 17.44 (11) for 3 and 46.1 (6) and 48.6 (6)° for 4, indicating that the –OH derivative is almost planar and the –Br derivative deviates the most from planarity. However, the substituent has no real influence on the bond distances in the α,β-unsaturated carbonyl moiety. The molecular packing of 1 features chain formation in the a-axis direction by O—H...O contacts. In the case of 2 and 3, the packing is characterized by dimer formation through C—H...O interactions. In addition, C—H...π(thiophene) interactions in 2 and C—H...S(thiophene) interactions in 3 contribute to the three-dimensional architecture. The presence of C—H...π(thiophene) contacts in the crystal of 4 results in chain formation in the c-axis direction. The Hirshfeld surface analysis shows that for all four derivatives, the highest contribution to surface contacts arises from contacts in which H atoms are involved.

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