C4–C5 fused pyrazol-3-amines: when the degree of unsaturation and electronic characteristics of the fused ring controls regioselectivity in Ullmann and acylation reactions
作者:Elisabeth Bou-Petit、Arnau Plans、Nieves Rodríguez-Picazo、Antoni Torres-Coll、Cristina Puigjaner、Mercè Font-Bardia、Jordi Teixidó、Santiago Ramon y Cajal、Roger Estrada-Tejedor、José I. Borrell
DOI:10.1039/d0ob00796j
日期:——
number of compounds with a wide range of biological activities and, in many cases, the heterocycle is C4–C5 fused to a second ring. Among the different reactions used for the decoration of the pyrazole ring, Ullmann and acylation have been widely applied. However, there is some confusion in the literature regarding the regioselectivity of such reactions (substitution at N1 or N2 of the pyrazole ring) and
吡唑-3-胺是存在于许多具有广泛生物活性的化合物中的支架,在许多情况下,杂环是C4–C5与第二个环稠合。在用于装饰吡唑环的不同反应中,Ullmann和酰化已得到广泛应用。然而,关于此类反应的区域选择性(吡唑环的N1或N2取代)的文献存在混淆,并且迄今尚未建立预测规则。作为我们对3-氨基-吡唑并[3,4- b ]吡啶酮的研究13,我们研究了在不同的C4–C5稠合的吡唑-3-胺中此类反应的区域选择性。根据经验,Ullmann和酰化反应主要发生在最稳定的初始互变异构体(1H-或2H-吡唑)的吡唑环的NH和非质子化氮原子上。通过使用DFT计算进行预测。
Rapid access to 3-aminoindazoles from nitriles with hydrazines: a strategy to overcome the basicity barrier imparted by hydrazines
A practical and efficient base mediated synthesis of free 3-aminoindazoles has been developed from the reaction of nitriles with hydrazines, which successfully overcomes the difficulty of using aromatic hydrazines as substrates and allows for the synthesis of a wide range of N-aryl substituted free 3-aminoindazoles in moderate to excellent yields under mild conditions in one-pot. This finding provides
Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines
作者:Yi Han、Mo Zhang、Ya-Qing Zhang、Zhan-Hui Zhang
DOI:10.1039/c8gc02611d
日期:——
inexpensive reagents and was employed as an effective support for heterogeneous copper. It was demonstrated that the obtained Cu@PI-COF is a highly active heterogeneous catalyst which can effectively promote the Chan–Lamcouplingreaction of aryl boronic acids and amines in an open flask without the aid of any base or additive. In addition, the catalyst could be readily recovered from the reaction mixture
3-Aminoindazole derivatives and process for preparation thereof
申请人:Asahi Kasei Kogyo Kabushiki Kaisha
公开号:EP0049779A1
公开(公告)日:1982-04-21
A compound of the formula (I):
wherein
W, is a hydrogen atom or a
group wherein Y is a C1-6 alkylene group or a C1-6 alkylene group having a C1-6 alkyl group substituent; and R, and R2 each independently is a hydrogen atom or a C1-6 alkyl group and R,, R2 and the adjacent nitrogen atom may form a C4-6 heterocyclic ring or a C4-6 heterocyclic ring containing an additional nitrogen atom and the C4-6 heterocyclic rings may have at least one C1-6 alkyl group, hydroxyl group or halogen atom;
W2 is a hydrogen atom or a
group wherein Z is a C1-6 alkylene group or a C1-6 alkylene group having a C1-6 alkyl group substituent; and R3 and R4 each independently is a hydrogen atom or a C1-6 alkyl group and R3, R4 and the adjacent nitrogen atom may form a C4-6 hetercyclic ring or a C4-6 heterocyclic ring containing an additional nitrogen atom and the C4-6 heterocyclic rings may have at least one C1-6 alkyl group, hydroxyl group or halogen atom;
when W, is a hydrogen atom, W2 is the
group; and
when W2 is a hydrogen atom, W, is the
group; and the pharmaceutically acceptable acid addition salt thereof.