Optimized conditions for Passerini-Smiles reactions and applications to benzoxazinone syntheses
Initial conditions disclosed for the Passerini-Smiles reaction are associated with a lack of efficiency that has prevented chemists from using it since its discovery. We wish to report herein our thorough study in the development of new experimental conditions for this coupling between electron-poor phenols, isocyanides, and carbonyl derivatives. These new conditions have been applied to several synthetic strategies towards benzoxazinones.
Copper-catalyzed oxidative cleavage of Passerini and Ugi adducts in basic medium yielding α-ketoamides
The aerobic oxidative cleavage of Passerini and Ugi adducts in the presence of base and copper(i) iodide is studied in detail. The oxidative cleavage yields α-ketoamides along with acids and amides from Passerini and Ugi adducts respectively. Mechanistic investigations revealed that the reaction proceeds via a radical pathway involving molecular oxygen. Control experiments with 18O-labeled Passerini adducts confirmed that molecular oxygen is the source of oxygen in α-ketoamides. A variety of Passerini and Ugi adducts were studied to explore the effect of substitution. Overall, the present study provides an insight into the reactivity of Passerini and Ugi adducts in strong basic conditions along with a method to prepare α-ketoamides.
Diverse Oxidative C(sp2)-N Bond Cleavages of Aromatic Fused Imidazoles for Synthesis of α-Ketoamides and N-(pyridin-2-yl)arylamides
An efficient and chemoselective C(sp2)-N bond cleavage of aromatic imidazo[1,2-a]pyridine molecules is developed. A broad scope of amide compounds such as α-ketoamides and N-(pyridin-2-yl)arylamides are afforded as the final products in up to quantitative yields. Diverse C-N bond cleavages are controlled by the oxidative species used in this transformation, with various amide products afforded in a chemoselective fashion. A preliminary study indicated that some α-ketoamides exhibit anti-Tobacco Mosaic Virus activity for potential use in plant protection.
Preparation method of alpha-carbonyl amide derivatives
The invention discloses a preparation method of alpha-carbonyl amide derivatives. According to the method, pyridino-aminoimidazole compounds and water are subjected to ring-opening reaction under theaction of an oxidizing agent, meanwhile, oxygen atoms ar
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Paragraph 0023-0025
(2019/01/14)
Ligand-Free Pd-Catalyzed Double Carbonylation of Aryl Iodides with Amines to α-Ketoamides under Atmospheric Pressure of Carbon Monoxide and at Room Temperature
A general Pd-catalyzed double carbonylation of aryl iodides with secondary or primary amines to produce α-ketoamides at atmospheric CO pressure has been developed. This transformation proceeds successfully even at room temperature and in the absence of any ligand and additive. A wide range of aryl iodides and amines can be coupled to the desired α-ketoamides in high yields with excellent chemoselectivities. Importantly, the current methodology has been demonstrated to be applied in the synthesis of bioactive molecules and chiral α-ketoamides.
Du, Hongyan,Ruan, Qing,Qi, Minghao,Han, Wei
supporting information
p. 7816 - 7823
(2015/08/18)
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