Facile synthesis of 1-substituted 5-trifluoromethylimidazole-4-carboxylates
作者:Wei Sheng Huang、Cheng Ye Yuan、Zhi Qin Wang
DOI:10.1016/0022-1139(95)03299-s
日期:1995.10
Base-induced cycloaddition of ethyl isocyanoacetates to trifluoroacetimidoyl chlorides gives ethyl 5-trifluoromethylimidazole-4-carboxylates with high regioselectivity.
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