The cationic ruthenium-hydride complex catalyzes the dehydrative C-H coupling reaction of arylamines with 1,2-diols to form the indole products. The analogous coupling of arylamines with 1,3-diols afforded the substituted, quinolines. The catalytic method directly forms these coupling products in a highly regioselective manner without generating any toxic byprodficts.
An efficient method for the direct synthesis of substituted quinolines from anilines and aldehydes through C–H functionalization, C–C/C–N bond formation, and C–C bond cleavage has been developed. The method is simple and practical and employs air as an oxidant.
Metal-Free, Ionic Liquid-Mediated Synthesis of Functionalized Quinolines
作者:Jaideep B. Bharate、Sandip B. Bharate、Ram A. Vishwakarma
DOI:10.1021/co500047w
日期:2014.11.10
An expedient and metal-free synthetic protocol for construction of substituted quinolines has been developed from anilines and phenylacetaldehydes using imidazolium cation-based ionic liquids as the reaction medium. Mechanistic analysis indicated that the reaction occurs through C-C and C-N bond formation to produce isolable 2,3-disubstituted quinoline intermediates, which undergo C-C bond cleavage to produce 3-substituted quinolines. The reaction proceeds smoothly with a range of functionalities in good to excellent yields. Advantages of this protocol include metal-free, environmentally friendly, recyclable reaction media, higher yields and shorter reaction times, and thus is promising for the efficient combinatorial synthesis of structurally diverse 2,3-disubstituted and 3-substituted quinolines.
Iron-Promoted Tandem Reaction of Anilines with Styrene Oxides via C–C Cleavage for the Synthesis of Quinolines
作者:Yicheng Zhang、Min Wang、Pinhua Li、Lei Wang
DOI:10.1021/ol300391t
日期:2012.5.4
A novel iron-promoted tandem reaction of anilines with styrene oxides via C-C cleavage and C-H activation has been developed. The reaction utilizes an inexpensive FeCl3 as promoter and is suitable for forming a variety of 3-aryiquinolines from the simple and readily available starting materials.