Achiral Cp x Ir(III)/Chiral Carboxylic AcidCatalyzed Enantioselective C–H Amidation of Ferrocenes underMild Conditions
2020
Ir(III)-catalyzed
enantioselective C–H activation generally
relies on the combination of chiral Ir(III) cyclopentadienyl complexes
with chiral carboxylic acids to ensure high enantiocontrol. We report
herein the achiral CpxIr(III)-catalyzed enantioselective
C–H amidation of ferrocenes. Crucial to the high enantioselectivity
is the use of a chiral carboxylic acid ligand derived from tert-leucine via Pd(II)-catalyzed γ-C(sp3)–H arylation and a sterically more hindered CpxIr(III) catalyst. This reaction proceeds smoothly under very mild
conditions (0 °C) and tolerates a wide range of ferrocene carboxamides
and dioxazolones, providing the amidation products in good yields
with high enantioselectivity (up to 97.5:2.5 er). This protocol might
open the way for achiral CpxIr(III)-catalyzed asymmetric
C–H activation.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
90
References
26
Citations
NaN
KQI