Synthesis of 6-Amino-, 6-Methyl- and 6-Aryl-2-(hydroxymethyl)purine Bases and Nucleosides

2006 ◽  
Vol 71 (6) ◽  
pp. 788-803 ◽  
Author(s):  
Peter Šilhár ◽  
Radek Pohl ◽  
Ivan Votruba ◽  
Blanka Klepetářová ◽  
Michal Hocek
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Purine Derivatives ◽  
Purine Bases ◽  
Arylboronic Acids ◽  
Cross Coupling Reactions ◽  
Zinc Iodide

An efficient methodology of the synthesis of 6-substituted 2-(hydroxymethyl)purine derivatives (bases and nucleosides) was developed. Regioselective Pd-catalyzed cross-coupling reactions of 6-chloro-2-iodopurines with [(benzoyloxy)methyl]zinc iodide gave 2-[(benzoyloxy)-methyl]-6-chloropurines that were converted to 2-(hydroxymethyl)adenines by reactions with ammonia and to 6-methyl- or 6-aryl-2-(hydroxymethyl)purines by cross-coupling reactions with trimethylaluminium or arylboronic acids followed by deprotection. The title 6-substituted 2-(hydroxymethyl)purine bases and nucleosides did not exhibit significant cytostatic or anti-HCV activity.

Synthesis of 2-Substituted 6-(Hydroxymethyl)purine Bases and Nucleosides

2005 ◽  
Vol 70 (10) ◽  
pp. 1669-1695 ◽  
Author(s):  
Peter Šilhár ◽  
Radek Pohl ◽  
Ivan Votruba ◽  
Michal Hocek
Keyword(s):  
Adenosine Deaminase ◽  
Cross Coupling ◽  
The Other ◽  
Coupling Reactions ◽  
Purine Derivatives ◽  
Cytostatic Effect ◽  
Purine Bases ◽  
Cross Coupling Reactions ◽  
Zinc Iodide

A facile and efficient methodology of the synthesis of 6-(hydroxymethyl)purine derivatives (bases and nucleosides) was developed based on Pd-catalyzed cross-coupling reactions of 6-halopurines or N-protected 2-amino-6-halopurines with (benzoyloxymethyl)zinc iodide followed by deprotection. Regioselective hydroxymethylations of 2,6-dihalopurines were also studied and used for the synthesis of 2-chloro-6-(hydroxymethyl)- or 2,6-bis(hydroxymethyl)purines. The 6-(hydroxymethyl)purine ribonucleoside 5f exerted high cytostatic effect and moderate inhibition of adenosine deaminase, while all the other derivatives were much less effective or entirely inactive.

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.

Efficient symmetrical bidentate dioxime ligand-accelerated homogeneous palladium-catalyzed Suzuki–Miyaura coupling reactions of aryl chlorides

2017 ◽  
Vol 41 (1) ◽  
pp. 372-376 ◽  
Author(s):  
Jinyi Song ◽  
Hongyan Zhao ◽  
Yang Liu ◽  
Huatao Han ◽  
Zhuofei Li ◽  
...  
Keyword(s):  
High Activity ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Bidentate Ligands ◽  
Aryl Chlorides ◽  
Arylboronic Acids ◽  
Mild Conditions ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

A series of N,O-bidentate ligands were synthesized and studied as high activity ligands for palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids under mild conditions.

Palladium-catalysed cross-coupling reactions of arylboronic acids with π-deficient heteroaryl chlorides

Tetrahedron ◽  
1992 ◽  
Vol 48 (37) ◽  
pp. 8117-8126 ◽  
Author(s):  
Naji M. Ali ◽  
Alexander McKillop ◽  
Michael B. Mitchell ◽  
Ricardo A. Rebelo ◽  
Philip J. Wallbank
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Arylboronic Acids ◽  
Cross Coupling Reactions
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