Combined Effects on Selectivity in Fe-Catalyzed Methylene Oxidation
作者:Mark S. Chen、M. Christina White
DOI:10.1126/science.1183602
日期:2010.1.29
in organic molecules. Methylene C–H bonds are among the most difficult chemical bonds to selectively functionalize because of their abundance in organicstructures and inertness to most chemical reagents. Their selective oxidations in biosynthetic pathways underscore the power of such reactions for streamlining the synthesis of molecules with complex oxygenation patterns. We report that an iron catalyst
A Reformatsky-type reaction has been developed using iron catalysis in acetonitrile or DMF. Reduction of iron(II) bromide by manganese metal in acetonitrile provides a low-valent iron catalyst, which is the active species; under these conditions, α-chloroesters or nitriles can both be converted into their corresponding derivatives. The method was applicable to both ketones and aldehydes, resulting in the formation of β-hydroxyesters under mild conditions.
β-hydroxy esters in the presence of catalytic amounts of the NiBr2(2,2′-bipyridine) complex has been developped from mixed electrolysis of methallylchloride, or methylchloroacetate with several carbonylcompounds, using a one-compartment cell equiped of a sacrificial zinc anode.
SUBSTITUTED AMINOPIPERIDINES AS DIPEPTIDYL PEPTIDASE-IV INHIBITORS FOR THE TREATMENT OF DIABETES
申请人:Cox Jason M.
公开号:US20120149683A1
公开(公告)日:2012-06-14
The present invention is directed to novel substituted aminopiperidines of structural formula I which are inhibitors of the dipeptidyl peptidase-IV enzyme and which are useful in the treatment or prevention of diseases in which the dipeptidyl peptidase-ÏV enzyme is involved, such as diabetes and particularly Type 2 diabetes. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the prevention or treatment of such diseases in which the dipeptidyl peptidase-IV enzyme is involved.
Reformatsky-type reactions have been performed efficiently using an electroassisted iron-complex catalysis. Valuable product such as beta-hydroxyesters, ketones or nitriles are thus prepared with high yields.