Regioselectivity of the protonation of captodative enamines bearing a CF3 group
摘要:
Capodative enamines bearing a CF3 group are protonated at the N- or beta-C-atom depending on the structure of the initial base and the nature of protonating reagent. (C) 2009 Elsevier B.V. All rights reserved.
Trifluoromethyl
ketones were found to be coupled with arynes in three modes depending upon their substitution patterns, namely CâC bond cleavage, [2+2] cycloaddition and O-arylation.
An intermolecularC(sp3)−Hamination reaction is reported that is promoted by internal oxidants and occurs via a C=N bond formation step. This intermolecularC(sp3)−Hamination reaction of trifluoromethyl ketones and aryldiazonium tetrafluoroborates affords various valuable trifluoroacetylated hydrazones in high yields with excellent E/Z selectivities. The salient features of this reaction type is
make biologically significant chiral β-hydroxy-α-amino-acid derivatives. But it is not easy to realize the transformation due to the disruption of the reactive NH2 group of glycinates. Inspired by the enzymatic aldol reaction of glycine, we successfully developed an asymmetric aldol reaction of glycinate 5 and trifluoromethyl ketones 4 with 0.1–0.0033 mol % of chiral N-methyl pyridoxal 7 a as the catalyst
Regioselectivity of the protonation of captodative enamines bearing a CF3 group
作者:Alexander Yu. Rulev、Igor A. Ushakov
DOI:10.1016/j.jfluchem.2009.10.001
日期:2010.1
Capodative enamines bearing a CF3 group are protonated at the N- or beta-C-atom depending on the structure of the initial base and the nature of protonating reagent. (C) 2009 Elsevier B.V. All rights reserved.