Synthesis of Cyclic Amidines from Quinolines by a Borane-Catalyzed Dearomatization Strategy
作者:Vinh Do Cao、So Hwa Mun、Seo Ha Kim、Gyeong Un Kim、Hyung Guk Kim、Seewon Joung
DOI:10.1021/acs.orglett.9b04275
日期:2020.1.17
herein is the development of a new synthetic route to cyclic amidinesfrom quinolines. The borane-catalyzed 1,4-hydrosilylation of quinoline was utilized for the dearomatization of the quinolines. The dearomatized enamine intermediate was subsequently reacted with a broad range of organic azides to produce the corresponding cyclic amidines (3,4-dihydroquinolinimines) via a [3 + 2] cycloaddition pathway
An operationally simple method with 100% atom economy has been developed for the synthesis of various N-(quinolin-2-yl)amides via the TsOH·H2O-mediated N-amidation of quinoline N-oxides using inexpensive and commercially available nitriles as the amidation reagents. Mechanistic exploration suggested that the reaction probably proceeds through an acid-assisted 1,3-dipolar cycloaddition and an N–O bond
Copper acetate-catalyzed C–H bond functionalization amination of quinoline N-oxides was achieved using O-benzoyl hydroxylamine as an electrophilic amination reagent, thereby affording the desired products in moderate to excellent yields.
Reductive C2-Alkylation of Pyridine and Quinoline <i>N</i>
-Oxides Using Wittig Reagents
作者:Sangil Han、Prashant Chakrasali、Jihye Park、Hyunjung Oh、Saegun Kim、Kyuneun Kim、Ashok Kumar Pandey、Sang Hoon Han、Soo Bong Han、In Su Kim
DOI:10.1002/anie.201807159
日期:2018.9.24
unprecedented reductive alkylation of pyridine and quinoline N‐oxides using Wittig reagents. A wide range of pyridine and quinoline N‐oxides were converted into C2‐alkylated pyridines and quinolines with excellent site selectivity and functional‐group compatibility. Sequential C−H functionalization reactions of pyridine and quinoline N‐oxides highlight the utility of the developed method. Detailed labeling
Metal-free methylation of a pyridine N-oxide C–H bond was developed using peroxide as a methyl reagent under neat conditions. Pyridine N-oxide derivatives with various groups (e.g., Cl, NO2, and OCH3) were all suitable substrates.