Synthesis of Functionalized Quinolines through a Reaction of Amides and Alkynes Promoted by Triflic Anhydride/Pyridine
作者:Lian-Hua Li、Zhi-Jie Niu、Yong-Min Liang
DOI:10.1002/chem.201703832
日期:2017.11.2
A concise, novel and flexible metal‐free single step to synthesize functionalized quinolines is reported. Triflic anhydride‐mediated (Tf2O) activation of amides is discussed in the presence of pyridine to offer strong electrophiles, thereby showcasing excellent productivity, high regio‐ and chemoselectivity, and widely tolerable substrates. This approach provides a straightforward and efficient way
Redox-Neutral Couplings between Amides and Alkynes via Cobalt(III)-Catalyzed C–H Activation
作者:Lingheng Kong、Songjie Yu、Xukai Zhou、Xingwei Li
DOI:10.1021/acs.orglett.5b03629
日期:2016.2.5
construction of heterocycles. This is ideally catalyzed by earth-abundant and eco-friendly transition metals. We report Co(III)-catalyzedredox-neutralcoupling between arenes and alkynes using an NH amide as an electrophilic directing group. The redox-neutral C–H activation/coupling afforded quinolines with water as the sole byproduct.
intermediate enables the switchable synthesis of quinoline and indole from amides and alkynes through C–H activation using Cp*Co(III). The keys to this strategy are (1) introducing a Lewis acid to greatly accelerate the dehydrative cyclization, which can outcompete dehydrogenative cyclization, and (2) tuning the directing group to facilitate the dehydrogenative cyclization and inhibit dehydrative cyclization