The Asymmetric Aza-Claisen Rearrangement: Development of Widely Applicable Pentaphenylferrocenyl Palladacycle Catalysts
作者:Daniel F. Fischer、Assem Barakat、Zhuo-qun Xin、Matthias E. Weiss、René Peters
DOI:10.1002/chem.200900712
日期:2009.9.7
has a broader substrate tolerance than all previously known catalyst systems for asymmetric aza‐Claisen rearrangements. Our investigations also reveal that subtle changes can have a big impact on the activity. With the enhanced catalyst activity, the asymmetric aza‐Claisen rearrangement has a very broad scope: the methodology not only allows the formation of highly enantioenriched primary allylic amines
Catalytic Asymmetric Rearrangement of Allylic <i>N</i>-Aryl Trifluoroacetimidates. A Useful Method for Transforming Prochiral Allylic Alcohols to Chiral Allylic Amines
作者:Larry E. Overman、Carolyn E. Owen、Mary M. Pavan、Christopher J. Richards
DOI:10.1021/ol0271786
日期:2003.5.1
useful method for the conversion of prochiral allylic alcohols to chiral allylic amines of high enantiopurity is reported. N-(4-Methoxyphenyl)trifluoroacetimidates are excellent substrates for the palladium(II)-catalyzed allylicimidaterearrangement as the allylic trifluoroacetamide products can be deprotected in two steps to provide chiral nonracemic allylic amines. Di-mu-chlorobis[(eta(5)-(S)-(pR)-
Synthesis of Nearly Enantiopure Allylic Amines by Aza-Claisen Rearrangement ofZ-Configured Allylic Trifluoroacetimidates Catalyzed by Highly Active Ferrocenylbispalladacycles
作者:Sascha Jautze、Paul Seiler、René Peters
DOI:10.1002/chem.200701642
日期:2008.2.8
semihydrogenations of alkynes. Our catalyst, a C(2)-symmetric planar chiral bispalladacycle complex, is rapidly prepared from ferrocene in four simple steps. Key step of this protocol is an unprecedented highly diastereoselective biscyclopalladation providing dimeric macrocyclic complexes of fascinating structure. In the present study as little as 0.1 mol % of catalyst precursor were sufficient for most
Asymmetric Synthesis of Heterobimetallic Planar Chiral Ferrocene Pallada-/Platinacycles and Their Application to Enantioselective Aza-Claisen Rearrangements
作者:Marcel Weiss、Wolfgang Frey、René Peters
DOI:10.1021/om300600v
日期:2012.9.10
corresponding bis-Pd complex, previously known to be the by far most active highly enantioselective catalyst for the rearrangement of Z-configured trifluoroacetimidates. This effect, which might be surprising at first sight due to the low efficiency of other Pt catalysts for aza-Claisenrearrangements, might be explained by an enhanced lifetime of a productive monodentate olefin coordination of the substrate
Practical, Highly Active, and Enantioselective Ferrocenyl–Imidazoline Palladacycle Catalysts (FIPs) for the Aza-Claisen Rearrangement ofN-para-Methoxyphenyl Trifluoroacetimidates
作者:Matthias E. Weiss、Daniel F. Fischer、Zhuo-qun Xin、Sascha Jautze、W. Bernd Schweizer、René Peters