Dichotomy in Regioselective Cross-Coupling Reactions of 6,8-Dichloropurines with Phenylboronic Acid and Methylmagnesium Chloride: Synthesis of 6,8-Disubstituted Purines.

ChemInform ◽  
2004 ◽  
Vol 35 (36) ◽  
Author(s):  
Michal Hocek ◽  
Dana Hockova ◽  
Hana Dvorakova
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

Comparison of the Suzuki cross-coupling reactions of 4,7-dichloroquinoline and 7-chloro-4-iodoquinoline with arylboronic acids using phosphine-free palladium catalysis in water

2004 ◽  
Vol 82 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Richard W Friesen ◽  
Laird A Trimble
Keyword(s):  
Phenylboronic Acid ◽  
Palladium Catalysis ◽  
Suzuki Reaction ◽  
Tetrabutylammonium Bromide ◽  
Cross Coupling ◽  
Palladium Acetate ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
Arylboronic Acids ◽  
Cross Coupling Reactions

4,7-Dichloroquinoline (1a) and 7-chloro-4-iodoquinoline (1b) undergo Suzuki cross-coupling reactions with arylboronic acids catalyzed by phosphine-free palladium acetate in boiling water. Using phenylboronic acid (2), the reaction of 1a provides 7-chloro-4-phenylquinoline (3) (78%) together with diphenylquinoline (4) (12%), while 1b reacts in a much more regioselective fashion and provides 3 in 98% isolated yield. Although 1b undergoes a more regioselective Suzuki reaction than 1a, additional important observations are that the overall reaction of 1b with 2 is three times slower than 1a and that the reaction occurs in the absence of tetrabutylammonium bromide. Using optimized reaction conditions, a variety of aryl and vinylboronic acids undergo regioselective Suzuki cross-coupling with 1b to provide the products 7, 10, and 11 in good to excellent yield.Key words: palladium, cross-coupling, regioselectivity, quinolines, boronic acids.

Cytostatic 6-Arylpurine Nucleosides V. Synthesis of 8-Substituted 6-Phenylpurine Ribonucleosides

2003 ◽  
Vol 68 (5) ◽  
pp. 837-848 ◽  
Author(s):  
Michal Hocek ◽  
Dana Hocková ◽  
Jan Štambaský
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Cytostatic Activity ◽  
Coupling Reactions ◽  
Nucleophilic Substitutions ◽  
Cross Coupling Reactions

Regioselective Suzuki-Miyaura reaction of 8-bromo-6-iodo-9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)purine with phenylboronic acid gave 8-bromo-6-phenylpurine derivative that was used for cross-coupling reactions (with PhB(OH)2, Me3Al, Et3Al, BnZnCl) or nucleophilic substitutions (with NaOH, NaOMe, NH3, NHMe2 or thiourea). A series of 8-X-substituted 6-phenyl-9-(β-D-ribofuranosyl)purines (X = Ph, Me, Et, Bn, OH, OMe, NH2, NMe2, SH) was prepared in this way directly or after deprotection. None of the title nucleosides exhibited any considerable cytostatic activity.

Magnetic Fe-Ni Alloy Catalyzed Suzuki Cross-Coupling Reactions of Aryl Halides with Phenylboronic Acid

ChemCatChem ◽  
2012 ◽  
Vol 5 (1) ◽  
pp. 142-145 ◽  
Author(s):  
Rongzhao Zhang ◽  
Chengxia Miao ◽  
Shoufeng Wang ◽  
Chungu Xia ◽  
Wei Sun
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Ni Alloy

Cytostatic 6-Arylpurine Nucleosides IV. Synthesis of 2-Substituted 6-Phenylpurine Ribonucleosides

2002 ◽  
Vol 67 (3) ◽  
pp. 325-335 ◽  
Author(s):  
Michal Hocek ◽  
Antonín Holý ◽  
Hana Dvořáková
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Cytostatic Activity ◽  
Coupling Reactions ◽  
Cross Coupling Reactions

A series of 2-X-substituted-6-phenyl-9-(β-D-ribofuranosyl)purines (X = Cl, Br, I, CH3, CF3and Ph) was prepared by halo-deaminations of protected 2-amino-6-phenylpurine ribonucleoside, by regioselective Suzuki-Miyaura reactions of 2,6-dihalopurines with phenylboronic acid or by cross-coupling reactions of the corresponding 2-halo-6-phenylpurines followed by deprotection. None of the title nucleosides exhibited any considerable cytostatic activity.

scholarly journals Palladium(II)-catalyzed Suzuki–Miyaura Reactions of Arylboronic Acid with Aryl Halide in the Presence of Aryl-Ferrocenyl-Phosphines

2013 ◽  
Vol 16 (1) ◽  
pp. 79
Author(s):  
A.T. Khabiyev ◽  
B.S. Selenova
Keyword(s):  
Catalytic Activity ◽  
Phenylboronic Acid ◽  
Potassium Phosphate ◽  
Cross Coupling ◽  
Phosphine Ligands ◽  
Catalyst Precursor ◽  
Coupling Reactions ◽  
Weak Base ◽  
Aryl Chlorides ◽  
Cross Coupling Reactions

<p>This study examined investigation of catalytic activity of aryl-ferrocenyl-phosphine (2-methoxyphenyl diferrocenyl phosphine (cat. 1), 2-tert-butyloxyphenyl diferrocenyl phosphine (cat. 2), 2-methoxynaphtyl diferrocenyl phosphine (cat. 3), 1,1’-bis(diphenylphosphino) ferrocene (cat. 4), phenyl diferrocenyl phosphine (cat. 5)) ligands with palladium salts as precursors in Suzuki–Miyaura reaction. Suzuki–Miyaura reaction is one of the important cross-coupling reactions and extremely powerful in forming C–C bonds. Aryl-ferrocenyl-phosphine ligands confer unprecedented activity for these processes, allowing reactions to be performed at low catalyst levels, to prepare extreme This study examined investigation of catalytic activity of aryl-ferrocenyl-phosphine (2-methoxyphenyl diferrocenyl phosphine (cat. 1), 2-tert-butyloxyphenyl diferrocenyl phosphine (cat. 2), 2-methoxynaphtyl diferrocenyl phosphine (cat. 3), 1,1’-bis(diphenylphosphino) ferrocene (cat. 4), phenyl diferrocenyl phosphine (cat. 5)) ligands with palladium salts as precursors in Suzuki–Miyaura reaction. Suzuki–Miyaura reaction is one of the important cross-coupling reactions and extremely powerful in forming C–C bonds. Aryl-ferrocenyl-phosphine ligands confer unprecedented activity for these processes, allowing reactions to be performed at low catalyst levels, to prepare extremely hindered biaryls and to be carried out, in general, also for reactions of aryl chlorides by temperature 100 ºC and pressure 1 atm. Sterically demanding and strongly Lewis-basic ferrocene-based phosphines are water- and oxygen-resistant. The Suzuki–Miyaura reaction is also an important reaction in the ground and fine organic synthesis, in the production of drugs and intermediates. To analyze the conversion of halogen aryl compounds the <sup>1</sup>H NMR spectroscopy was used. The advantage of Suzuki–Miyaura reaction in comparison with other cross-coupling reactions (Kumada-, Heck-, Heck-Carbonylation-, Murahashi-, Sonogashira-, Negishi-, Stille-reaktion, etc.) is in the usage of low toxic, water- and oxygen-insensitive thermostable organoboron compounds. As boronic acid was used phenylboronic acid and as weak base – potassium phosphate. Catalyst, precursor and weak base were dissolved in toluene. All reactions were performed under an atmosphere of nitrogen or argon. The catalytic cycle of Suzuki–Miyaura reaction typically includes three main steps: oxidative addition of the haloaromatic to catalytic active palladium (0) species, transmetalation, and reductive elimination of the product under back formation of catalytically active species. All used catalysts showed good activity with aryl bromides and weak activity with aryl chlorides.</p>

scholarly journals A Green Synthesis Strategy of Binuclear Catalyst for the C-C Cross-Coupling Reactions in the Aqueous Medium: Hiyama and Suzuki–Miyaura Reactions as Case Studies

2021 ◽  
Vol 9 ◽  
Author(s):  
Pouya Ghamari Kargar ◽  
Ghodsieh Bagherzade
Keyword(s):  
Aqueous Medium ◽  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Catalyst Characterization ◽  
High Catalytic Activity ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Successive Extraction ◽  
Nano Catalyst ◽  
Synthesis Strategy

Cellulose, as a green and available phytochemical, was immobilized on the surface of magnetite nanoparticles then doped with imidazole and Co. complex (Fe3O4@CNF ∼ ImSBL ∼ Co.) and used as a water-dispersible, recyclable and efficient nano catalyst for the synthesis of C−C cross-coupling reactions including fluoride-free Hiyama and Suzuki reactions in an aqueous medium as an efficient and vital solvent, due to their high application and importance in various fields of science. Different spectroscopic and microscopic techniques were used for the catalyst characterization such XRD, FESEM, TEM, FT-IR, EDX, DLS, VSM, UV-Vis, and ICP analyses. The presence of imidazole as ionic section tags with hydrophilic character on the Co-complex supported on magnetic nanoparticles provides dispersion of the catalyst particles in water, which leads to both higher catalytic performance and also facile catalyst recovery and reuse six times by successive extraction and final magnetic separation. High catalytic activity was found for the catalyst and high to excellent efficiency was obtained for all Suzuki (80–98% yield; E factor: 1.1–1.9) and Hiyama (87–98% yield; E factor: 0.26–1.1) derivatives in short reaction times under mild reaction conditions in the absence of any hazardous or expensive materials. There is not any noticeable by-product found whether for Suzuki or Hiyama derivatives, which reflects the high selectivity and also the lower the E factor the more favorable is the process in view of green chemistry. The bi-aryls were achieved from the reaction of various aryl iodides/bromides and even chlorides as the highly challenging substrates, which are more available and cheaper, with triethoxyphenylsilane or phenylboronic acid. To prove the performance of the catalyst components (synergistic of SBL ∼ Co. and IL), its different homologs were incorporated individually and studied for a model reaction. Exclusively, this is an introductory statement on the use of Cobalt binuclear symmetric ionic liquid catalysts in Hiyama reactions.

ChemInform Abstract: Magnetic Fe-Ni Alloy Catalyzed Suzuki Cross-Coupling Reactions of Aryl Halides with Phenylboronic Acid.

ChemInform ◽  
2013 ◽  
Vol 44 (23) ◽  
pp. no-no
Author(s):  
Rongzhao Zhang ◽  
Chengxia Miao ◽  
Shoufeng Wang ◽  
Chungu Xia ◽  
Wei Sun
Keyword(s):  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Ni Alloy
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