Dimetalation of pyrazines. a one-pot synthesis of multisubstituted pyrazine C-nucleosides.
Dimetalation of pyrazines. a one-pot synthesis of multisubstituted pyrazine C-nucleosides.
复制标题
吡嗪的二金属化。
DOI：
10.1021/jo001555f
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Townsend,LB
中科院分区：
文献类型：
--
作者：
Liu,W;Wise,DS;Townsend,LB
As a part of our efforts to pursue direct, convergent, and concise methodologies for the synthesis of pyrazineC-nucleosides, we have successfully established a sequential dilithiation−addition method, which allows one to introduce two different functional groups to a pyrazine ring in a one-pot fashion. 2,6-Dichloropyrazine was dilithiated at −100 °C and then allowed to react with an electrophile, such as bromine, iodine, or disulfides, followed by a reaction with a protected ribonolactone to affordC-nucleosides. After reduction and deprotection, tetrasubstituted pyrazineC-nucleosides, including 2,6-dichloro-3-iodo-5-(β-d-ribofuranosyl)pyrazine and 2-bromo-3,5-dichloro-6-(β-d-ribofuranosyl)pyrazine, were obtained. A tandem reaction sequence occurred when disulfides were used, resulting in the formation of 5,6-bis-methylthio-2-chloro-3-(β-d-ribofuranosyl)pyrazine and 6-(β-d-ribofuranosyl)-2,3,5-tris-phenylthiopyrazine.
