Chiral Phosphorus-Based 1,3-Dipoles: A Modular Approach to Enantioselective 1,3-Dipolar Cycloaddition and Polycyclic 2-Pyrroline Synthesis
作者:Marie S. T. Morin、Bruce A. Arndtsen
DOI:10.1021/ol4035512
日期:2014.2.21
design of a new class of chiral 1,3-dipoles for enantioselective cycloaddition reactions is reported. These phosphorus-based dipoles are easily formed (from imines, acid chlorides, and chiral phosphites), rigidly chiral, and undergo intramolecular alkene cycloaddition with high enantioselectivity. Overall, this provides a straightforward and modular approach to synthesize chiral 2-pyrrolines and pyrrolidines
Why Are BINOL-Based Monophosphites Such Efficient Ligands in Rh-Catalyzed Asymmetric Olefin Hydrogenation?
作者:Manfred T. Reetz、Andreas Meiswinkel、Gerlinde Mehler、Klaus Angermund、Martin Graf、Walter Thiel、Richard Mynott、Donna G. Blackmond
DOI:10.1021/ja052025+
日期:2005.7.1
based on BINOL-derived monodentate phosphites have resulted in an efficient and economically attractive preparative method, very little is known concerning the source of the unexpectedly high levels of enantioselectivity (ee often 90-99%). The present mechanistic study, which includes the NMR characterization of the precatalysts, kinetic measurements with focus on nonlinear effects, and DFT calculations