Conjugate Additions of <i>o</i>-Iodoanilines and Methyl Anthranilates to Acetylenic Sulfones. A New Route to Quinolones Including First Syntheses of Two Alkaloids from the Medicinal Herb <i>Ruta chalepensis</i>
作者:Thomas G. Back、Masood Parvez、Jeremy E. Wulff
DOI:10.1021/jo026595t
日期:2003.3.1
especially when the aniline contained an electron-withdrawing substituent such as an ester group. In some cases, the reactions were enhanced by the presence of DMAP and the use of an excess of the sulfone in aqueousDMF. N-Formylanilines proved superior to free anilines. The products were either vinyl or allyl sulfones, depending on the conditions and the structure of the reactants. The acetylenic sulfone
Close the ring to break the cycle: tandem quinolone-alkyne-cyclisation gives access to tricyclic pyrrolo[1,2-<i>a</i>]quinolin-5-ones with potent anti-protozoal activity
作者:Dávid Szamosvári、Kayla Sylvester、Philipp Schmid、Kuan-Yi Lu、Emily R. Derbyshire、Thomas Böttcher
DOI:10.1039/c9cc01689a
日期:——
We describe a tandem reaction leading to tricyclic pyrrolo[1,2-a]quinolin-5-ones with unique selectivity against the liver stage of the malaria parasite.
Novel access to 2-substituted quinolin-4-ones by nickel boride-mediated reductive ring transformation of 5-(2-nitrophenyl)isoxazoles
作者:Bernhard Lohrer、Franz Bracher
DOI:10.1016/j.tetlet.2019.151327
日期:2019.12
Reductive ring transformation of 3-substituted 5-(2-nitrophenyl)isoxazoles, readily accessible via 1,3-dipolar cycloaddition of 2-ethinylnitrobenzene with nitriles oxides, opens a novel access to 2-substituted quinolin-4-ones. Nickel boride, generated in situ from nickel chloride and sodiumborohydride, allows, via simultaneous reduction of the nitro group and reductive cleavage of the isoxazole ring, the
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.
Sequential Cu-Catalyzed Amidation-Base-Mediated Camps Cyclization: A Two-Step Synthesis of 2-Aryl-4-quinolones from <i>o</i>-Halophenones
作者:Carrie P. Jones、Kevin W. Anderson、Stephen L. Buchwald
DOI:10.1021/jo701384n
日期:2007.10.1
two-step method for the preparation of 2-aryl- and 2-vinyl-4-quinolones that utilizes a copper-catalyzed amidation of o-halophenones followed by a base-promoted Camps cyclization of the resulting N-(2-ketoaryl)amides is described. With CuI, a diamine ligand, and base as the catalyst system, the amidation reactions proceed in good yields for a range of aryl, heteroaryl, and vinyl amides. The subsequent Camps