RESUMO
A novel copper-catalyzed regioselective double carbonylation of imidazo[1,2-a]pyridines with N,N-disubstituted acetamide or acetone using molecular oxygen has been described. It has provided a new approach to synthesize 1,2-carbonyl imidazo[1,2-a]pyridines, which are important substrates and intermediates in preparation of fine chemicals. The product shares a skeleton similar to that of Zolpidem, one of the most prescribed drugs in the world. (18)O-labeling experiments unambiguously established that the oxygen source of products originated from O2 rather than H2O.
RESUMO
As a minimally invasive method, endovascular embolization has been an effective strategy for controlling bleeding and tumor treatment. Herein, carboxymethyl chitin embolic microspheres were prepared with the aqueous two-phase carboxymethyl chitin/polyethylene glycol system without using any crosslinking agents and thrombin-functionalized embolic microsphere named as Thr@CMCHm-30 was made after covalent introduction of thrombin. The size of the microspheres can be adjusted from 5 to 500 µm. The data of in vitro and in vivo tests indicated that these microspheres possessed good degradability and biocompatibility. Meanwhile, Thr@CMCHm-30 can significantly promote blood clotting and enhance the strength of the blood clots. More importantly, Thr@CMCHm-30 displayed better embolization effect than that of the commercial available Gelfoam Alicon® and polyvinyl alcohol-based embolic microspheres CalliSpheres® in rat femoral vein and rabbit ear artery embolization models. Therefore the size-tunable and biodegradable thrombin-functionalized carboxymethyl chitin microspheres Thr@CMCHm-30 possess great potential for effective hemostasis and endovascular embolization.
Assuntos
Quitina , Trombina , Animais , Hemostasia , Microesferas , Álcool de Polivinil , Coelhos , RatosAssuntos
Deficiência de Vitaminas/história , Ciências da Nutrição/história , Animais , Deficiência de Vitaminas/prevenção & controle , China , Diabetes Mellitus/história , Diabetes Mellitus/prevenção & controle , História do Século XX , Humanos , Neoplasias/história , Neoplasias/prevenção & controle , Doenças Neurodegenerativas/história , Doenças Neurodegenerativas/prevenção & controleRESUMO
An efficient copper-catalyzed selective cross coupling of imidazo[1,2-a]pyridines with methyl hetarenes has been reported. This transformation opened a new route to synthesize the C-3 carbonyl imidazo[1,2-a]pyridine derivative, which is a common structural motif in natural products and pharmaceuticals. (18)O-labeling experiments indicated that the oxygen source of products originated from O2.
RESUMO
Using the widely available DMSO as the formylation reagent under oxidative conditions, an efficient Cu-catalyzed C3-formylation reaction of imidazo[1,2-a]pyridine C-H bonds to directly generate structurally sophisticated 3-formyl imidazo[1,2-a]pyridine derivatives has been developed. The reaction proceeded to generate products in good yields, and used the environmentally friendly molecular oxygen as the oxidant.