On-water magnetic NiFe<sub>2</sub>O<sub>4</sub> nanoparticle-catalyzed Michael additions of active methylene compounds, aromatic/aliphatic amines, alcohols and thiols to conjugated alkenes
作者:Soumen Payra、Arijit Saha、Subhash Banerjee
DOI:10.1039/c6ra21160g
日期:——
Here, we have demonstrated the Michael addition of active methylene compounds, aromatic/aliphaticamines, thiols and alcohols to conjugated alkenes using magnetic nano-NiFe2O4 as reusable catalyst in water. Nano-NiFe2O4 efficiently catalyzed the formation of C–C and C–X (X = N, S, O etc.) bond through 1,4-addition reactions.
在这里,我们已经证明了使用磁性纳米NiFe 2 O 4作为在水中可重复使用的催化剂将活性亚甲基化合物,芳香族/脂肪族胺,硫醇和醇的迈克尔加成到共轭烯烃上。纳米NiFe 2 O 4通过1,4-加成反应有效催化了CC和CX (X = N,S,O等)键的形成。
Résumé The catalyst-free reactions of activated alkenes with primary and secondary amines were investigated leading to various mono- and di-hydroamination products, the latter being rare and original. These reactions were shown to depend first on the strength of the nucleophile. Temperature and steric hindrance of the reagents were the other key factors controlling the selectivity of these aza-Michael reactions. In spite of their poor nucleophilicities, some N-heterocyclic amines could react with different activated alkenes affording valuable intermediates. Such results tended to demonstrate the hydrogen-bonding interactions between activated alkenes and poly-nitrogen aromatic cycles may control these concerted or fully conjugate aza-Michael additions. Supplementary Materials: Supplementary material for this article is supplied as a separate file: mmc1.doc
A combination of gold chloride organometallic complex and a silver salt was used to catalyze intermolecular hydroamination of activated alkenes, i.e aza-Michael reactions. The gold-catalyzed reactions of activated alkenes with nitrogen substrates were investigated and found to afford various mono- and dihydroamination products, the latter being rare and original. After flash chromatography, gold NHC
TiCl<sub>2</sub>(OTf)-SiO<sub>2</sub>: A solid stable lewis acid catalyst for Michael addition of α-Aminophosphonates, Amines, Indoles and Pyrrole
作者:Habib Firouzabadi、Naser Iranpoor、Soghra Farahi
DOI:10.1080/10426507.2017.1417298
日期:2018.5.4
TiCl3(OTf) on silica gel surface and introduced as a non-hygroscopic Lewis acidcatalyst for C-N and C-C bond formation via Michaeladditionreaction. A variety of structurally diverse nitrogen nucleophiles including α-aminophosphonates, aliphatic and aromatic amines and imidazole were evaluated as Michael donors. Friedel–Crafts alkylation of indoles and pyrrole was also investigated through Michael addition
摘要 TiCl2(OTf)-SiO2 是通过将 TiCl3(OTf) 固定在硅胶表面上简单制备的,并作为非吸湿性路易斯酸催化剂引入,通过迈克尔加成反应形成 CN 和 CC 键。各种结构不同的氮亲核试剂,包括 α-氨基膦酸酯、脂肪族和芳香族胺以及咪唑被评估为迈克尔供体。在 TiCl2(OTf)-SiO2 作为催化剂存在下,通过迈克尔加成反应研究了吲哚和吡咯的 Friedel-Crafts 烷基化反应。反应在室温或 60 °C 下在无溶剂条件下进行,以高产率获得所需的迈克尔加合物。图形概要
Ruthenium‐ and Rhodium‐Catalyzed Dehydrogenative
<i>ortho</i>
‐Alkenylation of Benzylamines
<i>via</i>
Free Amino Group Directed CH Bond Cleavage
The dehydrogenativedirect coupling of α,α‐disubstituted benzylamines with acrylates takes place efficiently at room temperature under ruthenium catalysis, accompanied by freeaminogroup‐directedortho‐alkenylation and successive cyclization to produce (isoindol‐1‐yl)acetic acid derivatives. The reactions using styrenes in place of acrylates proceed effectively in the presence of a rhodium catalyst