Highly facile and regio-selective synthesis of pyrazolo[1,5-a]pyrimidines via reactions of 1,2-allenic ketones with aminopyrazoles
作者:Xinying Zhang、Yunping Song、Lin Gao、Xiaojie Guo、Xuesen Fan
DOI:10.1039/c3ob42445f
日期:——
An efficient procedure for the syntheses of pyrazolo[1,5-a]pyrimidines through reactions of 1,2-allenic ketones with aminopyrazoles under extremely mild conditions without using any catalyst or promoter has been developed. The reactions showed excellent regio-selectivity with all the allenic ketone substrates except for those bearing an alkyl group at the internal position of the allene moiety. The reason behind this regio-selectivity dissimilarity has been explored with the aid of the B3LYP/6-31G* level of density functional theory. Moreover, this novel procedure has been successfully applied in the preparation of nucleoside-pyrazolo[1,5-a]pyrimidine chimeras with potent antiviral activities.
Petrov; Emelina; Firsov, Russian Journal of Organic Chemistry, 2000, vol. 36, # 7, p. 1027 - 1032
作者:Petrov、Emelina、Firsov
DOI:——
日期:——
Convenient Synthesis of Substituted 3-Alkenylpyrazolo[1,5-<i>a</i>]pyrimidines via Heck Cross-Coupling Reaction
作者:Jürgen Liebscher、Lunxiang Yin
DOI:10.1055/s-2004-831189
日期:——
3-Iodopyrazolo[1,5-a]pyrimidines 3 were easily obtained by direct iodination of pyrazolol 1,5-a]pyrimidines 2 with NIS and could be transformed into a series of new substituted 3-alkenyl-pyrazolo[1,5-a]pyrimidines 5 by Heck cross-coupling.