Synthesis of Highly Fused Pyrano[2,3-<i>b</i>]pyridines via Rh(III)-Catalyzed C–H Activation and Intramolecular Cascade Annulation under Room Temperature
作者:Xu Han、Feng Gao、Chunpu Li、Daqing Fang、Xiong Xie、Yu Zhou、Hong Liu
DOI:10.1021/acs.joc.9b03102
日期:2020.5.15
A facile access to the polycyclic-fused pyrano[2,3-b]pyridines has been established under room temperature via Rh(III)-catalyzed C-H bond activation and intramolecular cascade annulation. This strategy features high efficiency, unique versatility, and generality and it can occur under mild conditions in good to excellent yields. More importantly, this strategy can be extended to the late-stage functionalization
A Comparative Investigation: Group 9 Cp*M(III)-Catalyzed Formal [4 + 2] Cycloaddition as an Atom-Economic Approach to Quinazolines
作者:Xiaoming Wang、Andreas Lerchen、Frank Glorius
DOI:10.1021/acs.orglett.6b00716
日期:2016.5.6
A comparative study on the catalytic activity of different group 9 [Cp*M(III)] complexes in the formal [4 + 2] cycloaddition of arenes with rarely explored free imines and dioxazolones for the construction of multisubstituted quinazolines is reported herein. This investigation revealed that the cobalt catalyst is uniquely suited to this transformation due to its strong Lewis acidity and high sensitivity
and expeditious protocol for the synthesis of difunctionalized indenes from readily available benzimidates and nitroalkenes through rhodium‐catalyzed C−H activation and cyclization is reported here. The transformation exhibits powerful reactivity, tolerates a large number of functionalgroups, and proceeds in moderate to high yields under an ambient atmosphere, providing a straightforward method to access
A Ru(II)-catalyzed C–H alkenylation of benzimidates with unactivated alkenes providing ortho-alkenylated benzonitriles in good to excellent yields in a highly regio- and stereoselective manner is described. In the reaction, an imidate group converted into a nitrile under the reaction conditions. The alkenylation reaction was compatible with various substituted benzimidates as well as functionalized
promising synthetic method; however, catalytic synthesis of 3,4-nonsubstituted isoquinolines by formal acetylene annulation has been scarce to date. Herein, we introduce vinyl selenone as an effective acetylene surrogate for the Rh-catalyzed annulative coupling under mild conditions. The Se fragment can be recovered as diselenide and recycled. The product can readily be converted to 1-aminoisoquinolines