Synthesis of 4-Quinolones via Cyclocondensation of Substituted ortho-Amidoacetophenones: A Refit to the Camps Cyclization by Applying Trimethylsilyl Trifluoromethanesulfonate/Triethylamine
A modification of the classical Camps cyclization is described. A series of substituted 4-quinolone derivatives is prepared via trimethylsilyl trifluoromethanesulfonate/triethylamine induced cyclocondensation of substituted ortho-amidoacetophenones. The process shows a broad substrate scope and allows selective preparation of 2-aryl- and 2-alkyl-substituted 4-quinolones. Enantiopure starting materials react without loss of optical purity using the modified conditions. Subsequent transformations of the products involving preparation of a 4-quinolyl nonaflate and O-selective methylation are also described.
Direct Synthesis of 2-Aryl-4-quinolones via Transition-Metal-Free Intramolecular Oxidative C(sp<sup>3</sup>)–H/C(sp<sup>3</sup>)–H Coupling
作者:Wei Hu、Jian-Ping Lin、Li-Rui Song、Ya-Qiu Long
DOI:10.1021/acs.orglett.5b00248
日期:2015.3.6
A novel, metal-free oxidative intramolecular Mannich reaction was developed between secondary amines and unmodified ketones, affording a simple and direct access to a broad range of 2-arylquinolin-4(1H)-ones through C(sp3)–H activation/C(sp3)–C(sp3) bond formation from readily available N-arylmethyl-2-aminophenylketones, using TEMPO as the oxidant and KOtBu as the base.
在仲胺和未改性的酮之间开发了一种新颖的,无金属的氧化性分子内曼尼希反应,可通过C(sp 3)-H活化简单直接地获得广泛的2-芳基喹啉4(1 H)-酮。/ C(sp 3)–C(sp 3)键由易于获得的N-芳基甲基-2-氨基苯基酮形成,使用TEMPO作为氧化剂,KO t Bu作为碱。
Supported palladium-catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes to access quinolin-4(1H)-ones
palladium supported on graphitic carbon nitride (Pd/g-CN) catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes has been developed for the expedite construction of quinolin-4(1)-one scaffolds. By using a low loading heterogeneous palladium catalyst, Mo(CO) as both the CO surrogate and the reductant, and nitroarenes as the nitrogen source, the reaction proceeded well to give a variety
In search for the new antimicrobial agents owing to drug resistant bacteria and fungi, a series of rationally designed aza analogs of flavones has been designed and synthesized. The design of the analogs involved incorporation of quinolone nucleus within the flavone framework keeping in view the antimicrobial potential of both the classes. The series of compounds was evaluated for the antibacterial
An Improved Environmentally Friendly Approach to 4-Nitro-, 4-Sulfonyl-, and 4-Aminoquinolines and 4-Quinolones through Conjugate Addition of Nucleophiles to β-(2-Aminophenyl)-α,β-ynones
led to valuable 4-sulfonylquinolines and 4-nitroquinolines. The latter proved to be versatile precursors of N-unsubstituted 4-aminoquinolines and 4-quinolones. Reaction of β-(2-aminophenyl)-α,β-ynones with DMF/NaOH resulted in the formation of 4-(dimethylamino)quinolines. The use of an alternative CO-free procedure for the preparation of substrates β-(2-aminophenyl)-α,β-ynones allowed extension of the