Treatment of alkyl α-(-heteroaryl)-α-diazoacetates with alkylating reagents affords diazoacetate N-heteroarenium salts. These novel 'onium' diazo compounds are mostly yellow solids, displaying increased thermal and acid stability. Their tetrafluoroborates undergo rhodium catalyzed [2 + 1] and Doyle-Kirmse reactions under mild conditions, suggesting the -quaternization an effective means of elimination of -coordination caused catalyst toxicity.
View Article and Find Full Text PDFA novel strategy for the catalytic synthesis of 2-aryl-2-benzo[][1,2,3]triazoles bearing a wide range of functional groups in good to excellent yields by non-noble molybdenum-catalyzed deoxygenative heterocyclization of 2-nitroazobenzenes is described. The salient features of the transformation include the use of readily available substrates, valuable products and ease of scale-up. The mechanistic study indicates that the reaction occurred double deoxygenation by the Mo(VI)/Mo(IV) catalytic cycle from 2-nitroazobenzene, through the formation of 2-aryl-2-benzo[][1,2,3]triazole--oxide or nitrene intermediates.
View Article and Find Full Text PDFBackground: To evaluate the efficacy and tolerability of capecitabine combined with thalidomide in patients with advanced pancreatic cancer (APC) who have previously received gemcitabine-based therapy.
Methods: A total of 31 patients were recruited prospectively in Shandong Tumor Hospital from May 2007 to April 2009. Capecitabine was offered to patients twice a day at a dose of 1250 mg/m(2) for 14-day then followed by 7-day rest.