Enabled by nickel catalysis, a practical access to the synthesis of 4-benzyl-3,3-difluoro-γ-lactams has been developed via radical tandem cyclisation/arylation. This method features a nickel catalyst, high reaction efficiency, and good substrate tolerance and scope. This protocol proceeds through an intramolecular radical addition to form a primary alkyl radical followed by intermolecular Suzuki-type coupling.
View Article and Find Full Text PDFOrg Biomol Chem
September 2017
A copper-catalysed tandem decarboxylation/aldol reaction of simple aromatic aldehydes with 2,2-difluoro-3-oxo-3-arylpropanoic acid has been developed under mild conditions. This method provides a new route for the direct one-pot synthesis of difluorinated aldols in moderate to good yields from simple substrates.
View Article and Find Full Text PDFDecarboxylative alkylation or acylation reactions of simple pyrimidines have been developed in aqueous media. Using aliphatic carboxylic acids or 2-oxocarboxylic acids and pyrimidines as substrates and silver as the catalyst, the 4-substituted alkyl or acyl pyrimidines were isolated in moderate to good yields.
View Article and Find Full Text PDFTwo mild and metal-free methods for the preparation of two kinds of important benzothiazole derivatives, 2-acylbenzothiazoles and dialkyl benzothiazol-2-ylphosphonates, respectively, were developed. The dialkyl H-phosphonate (RO)2P(O)H exists in equilibrium with its tautomer dialkyl phosphite (RO)2POH. TBHP triggered α-carbon-centered phosphite radical formation, whereas DTBP triggered phosphorus-centered phosphonate radical formation.
View Article and Find Full Text PDFA silver-catalyzed efficient and practical synthesis of 3-acyl-4-arylquinolin-2(1H)-ones or 3-acyl-4-aryldihydroquinolin-2(1H)-ones through intermolecular radical addition/cyclization in aqueous solution is reported. This method provides a novel, highly efficient, and straightforward route to substituted quinolin-2-ones or 3,4-dihydroquinolin-2-ones in one step. A possible mechanism for the formation of quinolin-2-ones is proposed.
View Article and Find Full Text PDFA silver-catalyzed tandem decarboxylative radical addition/cyclization of N-arylcinnamamides with aliphatic carboxylic acids is reported. This method affords a novel and straightforward route to various 3,4-disubstituted dihydroquinolin-2(1H)-ones in aqueous solution.
View Article and Find Full Text PDFA novel and easy practical direct synthesis of α-ketoamides has been developed without metals in water. This procedure was catalyzed by nBu(4)NI using TBHP as oxidant from simple substrates, aryl methyl ketones and dialkylformamides.
View Article and Find Full Text PDFChiral quaternary ammonium salts derived from cinchonidine have been applied to catalyze the stereoselective iodolactonizations of trans-5-aryl-4-pentenoic acids leading to a mixture of two regioselectively iodolactonized products with fair to excellent yield (37-98%) and moderate enantioselectivity (exo = 42.0% ee, endo = 31.0% ee) under mild conditions.
View Article and Find Full Text PDFYao Xue Xue Bao
August 2002
Aim: To study the thermal stability, decomposition process and kinetics of such purine pharmaceuticals as aciclovir (Acv), penciclovir (Pcv), and their parent substance, guanine.
Methods: Using infrared technique, accelerating test method and thermogravimetry to investigate the thermal decomposition processes and using Coast-Redfern method, MKN method and Ozawa method to deal with the data to get kinetic functions.
Results: The decomposition process and the formed products were derived, the kinetic model function was suggested by comparison of the kinetic parameters.