C–H Activation Guided by Aromatic N–H Ketimines: Synthesis of Functionalized Isoquinolines Using Benzyl Azides and Alkynes
摘要:
Aromatic N-H ketimines were in situ generated from various benzylic azides by ruthenium catalysis for the subsequent Rh-catalyzed annulation reaction with alkynes to give the corresponding isoquinolines. In contrast to conventional synthetic methods for aromatic NH ketimines, our protocol works under mild and neutral conditions, which enabled the synthesis of isoquinolines having various functionalities such as carbonyl, ester, alkenyl, and ether groups. In addition, the imidates generated from alpha-azido ethers were successfully used for the synthesis of 1-alkoxyisoquinolines.
The Rh(III)-catalyzed coupling of N-chloroimines with alkynes for the efficientsynthesis of isoquinolines is reported. This represents the first use of the N-Cl bond of N-chloroimines as an internal oxidant for construction of the isoquinoline skeleton. The synthesis features atom and step economy, a green solvent (EtOH), mild reaction conditions, and a broad substrate scope.2020 Elsevier Ltd. All
<i>N</i>-Tosylhydrazone directed annulation <i>via</i> C–H/N–N bond activation in Ru(<scp>ii</scp>)/PEG-400 as homogeneous recyclable catalytic system: a green synthesis of isoquinolines
作者:Dewal S. Deshmukh、Bhalchandra M. Bhanage
DOI:10.1039/c8ob01082j
日期:——
of isoquinolines using Ru(II)/PEG-400 as a homogeneous recyclable catalytic system has been demonstrated. N-Tosylhydrazone, a rarely explored directing group, has been successfully employed for an annulation type of reaction with alkynes viaC–H/N–N activation. A short reaction time with a simple extraction procedure, a wide substrate scope with high yields of products, easily prepared substrates, biodegradable
Cobalt(III)-Catalyzed Dehydrative [4+2] Annulation of Oxime with Alkyne by CH and NOH Activation
作者:Malay Sen、Deepti Kalsi、Basker Sundararaju
DOI:10.1002/chem.201503643
日期:2015.10.26
Efficient, scalable cobalt‐catalyzed redox‐neutral [4+2] annulation of readily available oximes and alkyne is reported. The developed synthetic methodology is widely applicable and tolerates various functional groups including heterocycles. A stable Cp*CoIII neutral complex is employed as the catalyst for this redox‐neutral [4+2] annulation reaction, which progresses smoothly by way of a reversible
据报道,高效,可扩展的钴催化的氧化还原中性[4 + 2]环化易于获得的肟和炔烃。所开发的合成方法学广泛适用,并能耐受包括杂环在内的各种官能团。稳定的Cp * Co III中性络合物用作该氧化还原-中性[4 + 2]环化反应的催化剂,该反应通过可逆的环金属化反应顺利进行,而无需任何外部氧化剂,仅产生水作为副产物。
Easy Access to 1-Amino and 1-Carbon Substituted Isoquinolines <i>via</i>
Cobalt-Catalyzed CH/NO Bond Activation
A green atom‐economical method for the synthesis of highly functionalized 1‐amino and 1‐carbon substituted isoquinolines from the reaction of N′‐hydroxybenzimidamides and aryl ketoximes, respectively, with alkynes via pentamethylcyclopentadienylcobalt(III)‐catalyzed CH/NO bond activation is described. The external oxidant‐free annulation reaction uses the =NOH moiety in N′‐hydroxybenzimidamides or
Pyridine synthesis from oximes and alkynesviarhodium(<scp>iii</scp>) catalysis: Cp* and Cp<sup>t</sup>provide complementary selectivity
作者:Todd K. Hyster、Tomislav Rovis
DOI:10.1039/c1cc15248c
日期:——
The synthesis of pyridines from readily available α,β-unsaturated oximes and alkynes under mild conditions and low temperatures using Rh(III) catalysis has been developed. It was found that the use of sterically different ligands allows for complementary selectivities to be achieved.