505092-89-7Relevant academic research and scientific papers
Pyrrole synthesis via allylic sp3 C-H activation of enamines followed by intermolecular coupling with unactivated alkynes
Rakshit, Souvik,Patureau, Frederic W.,Glorius, Frank
supporting information; experimental part, p. 9585 - 9587 (2010/09/10)
A conceptually novel pyrrole synthesis is reported, efficiently merging enamines and (unactivated) alkynes under oxidative conditions. In an intermolecular Rh catalyzed process, the challenging allylic sp3 C-H activation of the enamine substrates is followed by the cyclization with the alkyne (R3 = CO2R). Alternatively, in some cases (R 3 = CN), the enamine can be utilized for a vinylic sp2 C-H activation. A total of 17 examples with yields above 60% is presented, together with the results of an initial mechanistic investigation.
Synthesis of a new chiral bisphospholane ligand for the Rh(I)-catalyzed enantioselective hydrogenation of isomeric β-acylamido acrylates
Holz, Jens,Monsees, Axel,Jiao, Haijun,You, Jinsong,Komarov, Igor V.,Fischer, Christine,Drauz, Karlheinz,Boerner, Armin
, p. 1701 - 1707 (2007/10/03)
The highly stereoselective synthesis of a chiral silylphospholane has been described, which can be advantageously used as a building block under base-free conditions for the construction of diphosphines related to DuPHOS. The utility of silylphospholane is shown in the synthesis of a new bisphospholane ligand 1 (MalPHOS), which is characterized by a maleic anhydride backbone. The ligand forms with Rh(I) a complex with a larger bite angle P-Rh-P than the analogue Me-DuPHOS complex. Both complexes have been tested in the asymmetric hydrogenation of unsaturated α- and β-amino acid precursors of pharmaceutical relevance. In several cases, the new catalyst was superior in comparison to the Me-DuPHOS complex, in particular when (Z)-configured β-acylamido acrylates were used as substrates.
