3-Methylbutanal was obtained by the Strecker reaction with L-leucine and D-ribose at unelevated temperature and acidic conditions. Volatile compounds from reaction systems were analyzed by solid phase microextration ...3-Methylbutanal was obtained by the Strecker reaction with L-leucine and D-ribose at unelevated temperature and acidic conditions. Volatile compounds from reaction systems were analyzed by solid phase microextration （SPME） coupledwith gas chromatography-mass spectroscopy （GC-MS）. The formation mechanism of 3-methylbutanal was also proposed. Various reaction conditions were investigated, including reaction time, reaction temperature, pH value and salt content of the system.展开更多
We report a highly enantioselective one-pot facile synthesis of fluorinated Cα-tetrasubstituted amino nitriles from α-fluoroalkyl α-aryl keo tones, anilines, and TMSCN through a sequential p-TsOH catalyzed ketimine...We report a highly enantioselective one-pot facile synthesis of fluorinated Cα-tetrasubstituted amino nitriles from α-fluoroalkyl α-aryl keo tones, anilines, and TMSCN through a sequential p-TsOH catalyzed ketimine formation and chiral bifunctional tertiary amine mediated asymmetric Strecker reaction. This one-pot approach has two important advantages. First, it greatly improves the overall yield of the synthesis of chiral Cα-tetrasubstituted fluorinated aminonitriles from ketones, because the purification of a-fluorinated ketimines by column chromatography suffers from great yield loss. Second, it represents the first example of asymmetric tandem reactions that can simultaneously reuse the by-product and catalyst from the upstream step as a promoter and an additive to improve the reactivity and enantioselectivity of the subsequent catalytic enantioselective reaction, respectively. It could utilize the by-product H_2O generated in-situ from the ketimine formation step to activate TMSCN to form HCN, and concurrently reuse the remaining p-TsOH acid as an additive to improve enantioselectivity.展开更多
The synthesis and characterization of Zr-MCM-41 nanoreactors and their catalytic activity in the synthesis of new amino nitrile derivatives by the Strecker reaction in high yields and in short reaction times is reported.
文摘3-Methylbutanal was obtained by the Strecker reaction with L-leucine and D-ribose at unelevated temperature and acidic conditions. Volatile compounds from reaction systems were analyzed by solid phase microextration （SPME） coupledwith gas chromatography-mass spectroscopy （GC-MS）. The formation mechanism of 3-methylbutanal was also proposed. Various reaction conditions were investigated, including reaction time, reaction temperature, pH value and salt content of the system.
基金We thank the financial support from the National Natural Science Foundation of China （Nos. 21472049, 21725203）.
文摘We report a highly enantioselective one-pot facile synthesis of fluorinated Cα-tetrasubstituted amino nitriles from α-fluoroalkyl α-aryl keo tones, anilines, and TMSCN through a sequential p-TsOH catalyzed ketimine formation and chiral bifunctional tertiary amine mediated asymmetric Strecker reaction. This one-pot approach has two important advantages. First, it greatly improves the overall yield of the synthesis of chiral Cα-tetrasubstituted fluorinated aminonitriles from ketones, because the purification of a-fluorinated ketimines by column chromatography suffers from great yield loss. Second, it represents the first example of asymmetric tandem reactions that can simultaneously reuse the by-product and catalyst from the upstream step as a promoter and an additive to improve the reactivity and enantioselectivity of the subsequent catalytic enantioselective reaction, respectively. It could utilize the by-product H_2O generated in-situ from the ketimine formation step to activate TMSCN to form HCN, and concurrently reuse the remaining p-TsOH acid as an additive to improve enantioselectivity.
文摘The synthesis and characterization of Zr-MCM-41 nanoreactors and their catalytic activity in the synthesis of new amino nitrile derivatives by the Strecker reaction in high yields and in short reaction times is reported.
