Dirhodium Chiral Complexes for Catalytic Stereoselective Preparation
Dirhodium tetracarboxylate complexes have been extensively studied over the past few decades. There has been an interest in respect to their applications in catalysis and in particular for a wider number of selective transformations such as intermolecular and intramolecular C-H insertion, cycloaddition and other organic reactions. Insertions of a carbene or nitrene into unactivated C–H bonds, promoted by donor/acceptor-substituted Rh carbenoid, have gained special attention.[1-2] Most of these catalysts are notable for their stereoselectivity as well as their stability when exposed to heat, moisture or ambient atmospheres.
Strem offers dirhodium paddle-wheel structured chiral catalysts which were developed within the last few years. These products have opened up new possibilities for researchers. Rh2(R,S-PTAD)4 (45-2070: R-modification, 45-2071: S-modification) is useful for intermolecular cyclopropanation of olefins with R-aryl-R-diazo ketones, cyclopropanation reactions of diazo compounds with cyano group, asymmetric of diazo sulfonylamidines and other reactions. Catalysts Rh2(R-BTPCP)4 (45-2080: R-modification, 45-2081: S-modification) and Rh2(R-DOSP)4 (45-2100 R-modification, 45-2101 S-modification) are also used for enantioselective cyclopropanation as well as asymmetric synthesis.
Rh2(S-PTTL)4 (45-2105) is a recent addition to our catalogue. This catalyst is not only applicable for customary dirhodium catalytic reactions, but also allows certain adducts to be extracted from the reaction mixture with a very high purity. This quality is what makes this catalyst interesting for biomedical applications.
In addition to chiral catalysts, Strem offers a classical halogen free dirhodium complex (45-0390) [Rh(OMe)(COD)]2 which can be used both as a catalyst and also for organometallic and nano preparations.