Hypervalent Iodine(III)‐Mediated Regioselective Cyanation of Quinoline
<i>N</i>
‐Oxides with Trimethylsilyl Cyanide
作者:Feng Xu、Yuqin Li、Xin Huang、Xinjie Fang、Zhuofei Li、Hongshuo Jiang、Jingyi Qiao、Wenyi Chu、Zhizhong Sun
DOI:10.1002/adsc.201801185
日期:2019.2
A regioselective cyanation of quinoline N‐oxides with trimethylsilyl cyanide was developed by using (Diacetoxyiodo) benzene (PIDA) as mediated hypervalentiodine(III) reagent under metal‐free and base‐free reaction conditions to obtain 2‐cyanoquinolines. The efficient PIDA reagent could play the role of an activator of the substrates and an accelerator of N−O bond cleavage. The reaction system featured
azaheterocycle N-oxides with alkenes catalyzed by iodine under metal- and external oxidant-free reaction conditions has been developed. A variety of (E)-2-styrylazaheterocycles have been produced in moderate to excellent yields. The mechanistic exploration indicated that the N-oxide group played dual roles as both the directing group and an internal oxidant in this catalytic cycle.
The first nickel-catalyzed CH trifluoromethylation of pyridineN-oxides with Togni’s reagent has been achieved. Trifluoromethylation proceeds smoothly under mild conditions with moderate functional group compatibility. Notable advantages of this method include the using of low cost of nickel catalyst, and its simple convenient operation.
Regioselective deoxygenative C H trifluoromethylthiolation of heteroaryl N-oxides with AgSCF3
作者:Shi-Bo Zhang、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1016/j.jfluchem.2019.109367
日期:2019.11
trifluoromethylthiolation of heteroaryl N-oxides with AgSCF3 is presented, employing p-toluenesulfonic anhydride and tetra-n-butylammonium iodide as the activators. This reaction delivers a series of C2-trifluoromethylthiolated heteroaromaticcompounds in moderate to excellent yields. It provides a complementary method for CH trifluoromethylthiolation reactions.
Cp*Rh(III)-Catalyzed Directed C−H Methylation and Arylation of Quinoline <i>N</i>
-Oxides at the C-8 Position
作者:Bao Wang、Chunpu Li、Hong Liu
DOI:10.1002/adsc.201700484
日期:2017.9.4
Herein, we report a Cp*Rh(III)‐catalyzed directed C−H methylation of quinolineN‐oxides at the C‐8 position using commercially available organotrifluoroborates as reagents. This method features perfect regioselectivity, relatively mild reaction conditions, and diverse functional group tolerance with good to excellent yields. Additionally, direct C‐8 arylated quinolineN‐oxides products could also be obtained