α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles
作者:Uroš Grošelj、Mojca Žorž、Amalija Golobič、Branko Stanovnik、Jurij Svete
DOI:10.1016/j.tet.2013.11.008
日期:2013.12
simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose
Vinylation of α-Aminoazoles with Triethylamine: A General Strategy to Construct Azolo[1,5-<i>a</i>]pyrimidines with a Nonsubstituted Ethylidene Fragment
作者:Qinghe Gao、Zhenhua Sun、Qinfei Xia、Ruonan Li、Wenlong Wang、Siwei Ma、Yixin Chai、Manman Wu、Wei Hu、Péter Ábrányi-Balogh、György M. Keserű、Xinya Han
DOI:10.1021/acs.orglett.1c00571
日期:2021.4.2
A new general synthesis of pharmaceutically important azolo[1,5-a]pyrimidines starting from widely available 3(5)-aminoazoles, aldehydes, and triethylamine is developed. The key is to enable the vinylation reaction that allows the in situ generation of elusive acyclic enamines and the subsequent annulation reaction to occur. This direct and practical strategy is capable of constructing a range of 5
从广泛可用的3(5)-氨基唑,醛和三乙胺开始,开发了一种重要的药学上重要的偶氮[1,5- a ]嘧啶的新的一般合成方法。关键是要实现乙烯基化反应,该反应可以原位产生难以捉摸的无环烯胺,并随后发生环化反应。这种直接而实用的策略能够构建一系列5,6-未取代的吡唑并[1,5- a ]嘧啶和[1,2,4]三唑并[1,5- a ]嘧啶。更重要的是,该方案为制备临床使用的扎来普隆提供了一种简明的合成途径。
Regioselective synthesis of 1- and 4-substituted 7-oxopyrazolo[1,5-a]pyrimidine-3-carboxamides
作者:Miha Drev、Uroš Grošelj、Špela Mevec、Eva Pušavec、Janja Štrekelj、Amalija Golobič、Georg Dahmann、Branko Stanovnik、Jurij Svete
DOI:10.1016/j.tet.2014.09.020
日期:2014.11
The synthesis of 7-substitutedpyrazolo[1,5-a]pyrimidine-3-carboxamides was studied. First, methyl 7-hydroxypyrazolo[1,5-a]pyrimidine-3-carboxylate (5) was prepared in three steps from methyl 5-amino-1H-pyrazole-4-carboxylate (3). Treatment of 5 with POCl3 gave the highly reactive 7-chloro derivative 10, which was reacted with amines, benzyl alcohol, and phenylboronic acid in the presence of Pd-catalyst
研究了7-取代的吡唑并[1,5 - a ]嘧啶-3-羧酰胺的合成。首先,分三步从5-氨基-1 H-吡唑-4-羧酸甲酯(3)制备7-羟基吡唑并[1,5- a ]嘧啶-3-羧酸甲酯(5)。用POCl 3处理5得到高反应性的7-氯衍生物10,其在Pd-催化剂的存在下与胺,苯甲醇和苯基硼酸反应,得到相应的7-取代的衍生物11。酯5和11的水解,然后酰胺化,得到相应的羧酰胺16a – h和15。7-羟基吡唑并[1,5- a ]嘧啶-3-羧酸衍生物5和16的N-烷基化的区域选择性可通过羧基官能团调节。仲酰胺16a - f的烷基化提供了1-烷基衍生物17a - f,而酯5和叔酰胺16g,h则选择性地提供了4-烷基衍生物14a - d和16m,n。
An Approach for the Synthesis of Pyrazolo[1,5-<i>a</i>]pyrimidines via Cu(II)-Catalyzed [3+3] Annulation of Saturated Ketones with Aminopyrazoles
A one-step synthesis of diversely substituted pyrazolo[1,5-a]pyrimidines from saturated ketones and 3-aminopyrazoles is presented. This transformation involves the in situ formation of α,β-unsaturatedketones via a radical process, followed by [3+3] annulation with 3-aminopyrazoles in onepot. Mechanistic studies have shown that the dual C(sp3)–H bond functionalization of inactive ketones is required
提出了从饱和酮和 3-氨基吡唑一步合成不同取代的吡唑并[1,5- a ]嘧啶。这种转化涉及通过自由基过程原位形成 α,β-不饱和酮,然后在一个锅中与 3-氨基吡唑进行 [3+3] 环化。机理研究表明,形成标题化合物需要非活性酮的双 C(sp 3 )-H 键官能化。值得注意的是,这种脱氢偶联过程提供了从市售底物获得大量具有抗肿瘤潜力的官能化吡唑并[1,5- a ]嘧啶的途径。