Ethylene Glycol: A Powerful Catalyst‐Free Medium for CC Bond‐Forming Reactions
作者:Yun‐Lin Liu、Xing‐Ping Zeng、Jian Zhou
DOI:10.1002/asia.201200289
日期:2012.8
A good EG: Ethylene glycol (EG) is a catalyst‐free medium that can promote the highly efficient Strecker reaction of α‐CF2H or α‐CF3 ketoimines and TMSCN. EG was used in several reactions, including the catalyst‐free Morita–Baylis–Hillman reaction.
The first organocatalytic enantioselective Streckersynthesis of α-quaternary α-trifluoromethylated amino acids has been developed. Employing Takemoto’s thiourea catalyst the nucleophilic addition of trimethylsilyl cyanide to trifluoromethyl ketimines affords α-amino nitriles in good to excellent yields (50–99%) and very good enantioselectivities (ee=83–95%). The enantiopure amino nitriles can be obtained