Synergistic Indium and Silver Dual Catalysis: A Regioselective [2 + 2 + 1]-Oxidative <i>N</i>-Annulation Approach for the Diverse and Polyfunctionalized <i>N</i>-Arylpyrazoles
作者:Raju S. Thombal、Yong Rok Lee
DOI:10.1021/acs.orglett.8b02008
日期:2018.8.3
Indium(III)/silver(I)-catalyzed [2 + 2 + 1] annulation of arylhydrazine hydrochlorides with β-enamino esters via multicomponent reactions for the construction of diverse and multisubstituted N-arylpyrazoles has been demonstrated. The oxidative cycloaddition proceeds via a cascade triple Michael addition/elimination/air oxidation. This novel protocol provides a rapid and efficient synthetic route to
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。
Lewis Acid-Promoted Three-Component Reactions of Propargylic Alcohols with 2-Butynedioates and Secondary Amines
作者:Guangwei Yin、Yuanxun Zhu、Ping Lu、Yanguang Wang
DOI:10.1021/jo2016407
日期:2011.11.4
We report herein a three-component reaction of propargylic alcohols with 2-butynedioates and secondaryamines, which furnished functionalized dihydroazepines. In the cases where benzylmethylamine and benzyl-i-propylamine were used as the secondaryamine, the reaction afforded 2,5-dihydro-1H-pyrroles and 2,3-dihydro-1H-pyrroles, respectively, as the major product along with the desired dihydroazepines
Preparation of 6-Unsubstituted 3,4-Dihydropyrimidin-2(1H)-Ones and 2-(Arylamino)Pyrimidines
作者:S. Terentjeva、D. Muceniece、V. Lusis
DOI:10.1007/s10593-014-1428-0
日期:2014.3
methyl propiolate and of methyl 3-diethylaminoacrylate has yielded a novel series of 6-unsubstituted 3,4-dihydropyrimidin-2(1H)-ones. The successie oxidation of the pyrimidine ring, chlorination of the 2-oxo group, and substitution of the chlorine atom by an aromatic amine give previously unknown 2-(arylamino)pyrimidines. 2-Oxo- and 2-(arylamino)pyrimidine-5-carboxylic acids have been obtained.
Regioselective construction of diverse and multifunctionalized 2-hydroxybenzophenones for sun protection by indium(<scp>iii</scp>)-catalyzed benzannulation
作者:Hongyun Cai、Likai Xia、Yong Rok Lee
DOI:10.1039/c6cc02381a
日期:——
Highly regioselective synthesis of 2-hydroxybenzophenones via the In(OTf)3-catalyzed formal [2+2+2] and [4+2] benzannulations has been successfully developed and their application as sun protection materials was also evaluated.