SNAr Iodination of 6-Chloropurine Nucleosides: Aromatic Finkelstein Reactions at Temperatures Below −40 °C1
摘要:
Mesitoyl or toluoyl esters of inosine and 2'-deoxyinosine were deoxychlorinated at C6 to give the crystalline 6-chloropurine nucleoside derivatives, which underwent quantitative conversion to the 6-iodo analogues with Nal/TFA/butanone at -50 to -40 degreesC. The 6-iodo compounds were efficient substrates for SNAr, Sonogashira, and Suzuki-Miyaura reactions, in contrast with the 6-chloro analogues, and gave good to high yields of C-N and C-C coupled products.
SNAr Iodination of 6-Chloropurine Nucleosides: Aromatic Finkelstein Reactions at Temperatures Below −40 °C1
摘要:
Mesitoyl or toluoyl esters of inosine and 2'-deoxyinosine were deoxychlorinated at C6 to give the crystalline 6-chloropurine nucleoside derivatives, which underwent quantitative conversion to the 6-iodo analogues with Nal/TFA/butanone at -50 to -40 degreesC. The 6-iodo compounds were efficient substrates for SNAr, Sonogashira, and Suzuki-Miyaura reactions, in contrast with the 6-chloro analogues, and gave good to high yields of C-N and C-C coupled products.
Selective Removal of the 2‘- and 3‘-<i>O</i>-Acyl Groups from 2‘,3‘,5‘-Tri-<i>O</i>-acylribonucleoside Derivatives with Lithium Trifluoroethoxide<sup>1</sup>
作者:Ireneusz Nowak、Carl T. Jones、Morris J. Robins
DOI:10.1021/jo0600104
日期:2006.4.1
Selective cleavage of O2' and O3' ester groups from ribonucleoside derivatives has been accomplished with Dowex 1 x 2 (CF3CH2O-) in 2,2,2-trifluoroethanol (TFE) or lithium trifluoroethoxide/TFE. Deacylations with Li+ -OCH2CF3/TFE proceed at ambient temperature (or with mild heating) to give the 5'-O-acyl derivatives in superior yields and higher purity than prior approaches for selective O2' and O3' ester deprotection.
S<sub>N</sub>Ar Iodination of 6-Chloropurine Nucleosides: Aromatic Finkelstein Reactions at Temperatures Below −40 °C<sup>1</sup>
作者:Jiangqiong Liu、Zlatko Janeba、Morris J. Robins
DOI:10.1021/ol048987n
日期:2004.8.1
Mesitoyl or toluoyl esters of inosine and 2'-deoxyinosine were deoxychlorinated at C6 to give the crystalline 6-chloropurine nucleoside derivatives, which underwent quantitative conversion to the 6-iodo analogues with Nal/TFA/butanone at -50 to -40 degreesC. The 6-iodo compounds were efficient substrates for SNAr, Sonogashira, and Suzuki-Miyaura reactions, in contrast with the 6-chloro analogues, and gave good to high yields of C-N and C-C coupled products.