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.

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.

Cytostatic 6-Arylpurine Nucleosides II. Synthesis of Sugar-Modified Derivatives: 9-(2-Deoxy-β-D-erythro-pentofuranosyl)-, 9-(5-Deoxy-β-D-ribofuranosyl)- and 9-(2,3-Dihydroxypropyl)-6-phenylpurines

2000 ◽  
Vol 65 (11) ◽  
pp. 1683-1697 ◽  
Author(s):  
Michal Hocek ◽  
Antonín Holý ◽  
Ivan Votruba ◽  
Hana Dvořáková
Keyword(s):  
Cross Coupling ◽  
Cytostatic Activity ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Highly Active ◽  
Phenylboronic Acids

9-(2-Deoxy-β-D-erythro-pentofuranosyl)-6-(4-substituted phenyl)purines, 9-(5-deoxy-β-D-ribofuranosyl)-6-(4-substituted phenyl)purines and 9-(2,3-dihydroxypropyl)-6-(4-substituted phenyl)purines were prepared by the Suzuki-Miyaura cross-coupling reactions of the corresponding protected 9-substituted 6-chloropurines with substituted phenylboronic acids followed by MeONa mediated deprotection. In contrast to the highly active 6-phenylpurine ribonucleosides, the title compounds did not show any considerable cytostatic activity.

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 and Antiviral 6-Arylpurine Ribonucleosides VIII. Synthesis and Evaluation of 6-Substituted Purine 3'-Deoxyribonucleosides

2006 ◽  
Vol 71 (10) ◽  
pp. 1484-1496 ◽  
Author(s):  
Michal Hocek ◽  
Peter Šilhár ◽  
Radek Pohl
Keyword(s):  
Cross Coupling ◽  
Cytostatic Activity ◽  
Coupling Reactions ◽  
Alkyl Aryl ◽  
Cross Coupling Reactions

A series of purine 3'-deoxyribonucleosides bearing diverse C-substituents (alkyl, aryl, hetaryl or hydroxymethyl) in the position 6 was prepared by Pd-catalyzed cross-coupling reactions of 6-iodo-9-[2,5-bis-O-(tert-butyldimethylsilyl)-3-deoxy-β-D-ribofuranosyl]purine with the corresponding organometallics followed by deprotection by (HF)3·Et3N. None of the title 3'-deoxyribonucleoside showed any cytostatic activity or anti-HCV effect in replicon assay.

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 III. Synthesis and Structure-Activity Relationship Study in Cytostatic Activity of 6-Aryl-, 6-Hetaryl- and 6-Benzylpurine Ribonucleosides

2001 ◽  
Vol 66 (3) ◽  
pp. 483-499 ◽  
Author(s):  
Michal Hocek ◽  
Antonín Holý ◽  
Ivan Votruba ◽  
Hana Dvořáková
Keyword(s):  
Cross Coupling ◽  
Structure Activity Relationship ◽  
Cytostatic Activity ◽  
Activity Relationship ◽  
Coupling Reactions ◽  
Arylboronic Acids ◽  
Cross Coupling Reactions ◽  
Structure Activity ◽  
Relationship Study

A series of fifteen 6-aryl-, 6-hetaryl- and 6-benzylpurine ribonucleosides has been prepared by Pd-catalyzed cross-coupling reactions of 6-chloro-9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)- purine with arylboronic acids, hetarylzinc halides, hetarylstannanes or benzylzinc halides followed by deprotection. Structure-activity relationship study revealed that besides 6-(4-substituted phenyl)purine nucleosides, also some 6-hetaryl- and 6-benzylpurine ribonucleosides possess 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>

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