Combining enabling techniques in organic synthesis: solid-phase-assisted catalysis under microwave conditions using a stable Pd(II)-precatalyst
作者:Kamal M. Dawood、Andreas Kirschning
DOI:10.1016/j.tet.2005.07.113
日期:2005.12
2-pyridinealdoxime-based Pd(II)-complex covalently anchored via the oxime moiety to a glass/polymer composite material was evaluated in Suzuki–Miyaura cross-coupling reactions of aryl and heteroaryl halides, including arylchlorides, with aryl and heteroaryl boronic acids both under thermal as well as microwaveirradiatingconditions in water. The stability and reusability of this Pd-precatalyst is part
Cobalt in Organic Synthesis Abstract A robust and scalable CoCl2-catalyzed cross-coupling between functionalized arylzinc pivalates and various electron-poor (hetero)aryl and alkenyl halides is reported. A robust and scalable CoCl2-catalyzed cross-coupling between functionalized arylzinc pivalates and various electron-poor (hetero)aryl and alkenyl halides is reported.
alcohols, benzaldehydes, and DMSO to quinolines has been disclosed. For the reported annulation between 2-aminobenzyl alcohols and benzaldehydes, the change of the solvent from toluene to DMSO led to the change of the product from the diheteroatomic cyclic benzoxazines to monoheteroatomic cyclic quinolines. This annulation can be used to synthesize regioselectively different substituted quinolines
[3+1+1+1] Annulation to the Pyridine Structure in Quinoline Molecules Based on DMSO as a Nonadjacent Dual-Methine Synthon: Simple Synthesis of 3-Arylquinolines from Arylaldehydes, Arylamines, and DMSO
A [3+1+1+1] annulation of arylamines, arylaldehydes, and dimethyl sulfoxide (DMSO) to the pyridine structure in quinolines using DMSO as a nonadjacent dual-methine (═CH−) synthon is disclosed. In this annulation, arylamines provide two carbon atoms and one nitrogen atom, arylaldehydes furnish one carbon atom, and DMSO provides two nonadjacent methines (═CH−) to the pyridine ring in quinoline molecules
Cobalt‐Catalyzed C8‐Dienylation of Quinoline‐
<i>N</i>
‐Oxides
作者:Rahul K. Shukla、Akshay M. Nair、Salman Khan、Chandra M. R. Volla
DOI:10.1002/anie.202003216
日期:2020.9.21
An efficient Cp*CoIII‐catalyzed C8‐dienylation of quinoline‐N‐oxides was achieved by employing allenes bearing leaving groups at the α‐position as the dienylating agents. The reaction proceeds by CoIII‐catalyzed C−H activation of quinoline‐N‐oxides and regioselective migratory insertion of the allene followed by a β‐oxy elimination, leading to overall dienylation. Site‐selective C−H activation was
喹啉N-氧化物的有效Cp * Co III催化C8-二烯基化反应是通过使用在α-位带有离去基团的烯作为二烯化剂来实现的。该反应通过Co III催化喹啉N氧化物的CH H活化和丙二烯的区域选择性迁移插入,然后被β氧基消除而进行,从而导致整体二烯化。在温和的反应条件下,以优异的选择性实现了位点选择性的CH活化,并且发现30 mol%的NaF添加剂对于有效的二烯基化至关重要。该方法具有高立体选择性,温和的反应条件和良好的官能团耐受性。喹啉N的C8烯基化在没有离开基团作为偶联配偶体的丙二烯的情况下实现了氧化。此外,进行了克级制备和初步的机理实验,以深入了解反应机理。