Direct Access to 4,5‐Disubstituted [2.2]Paracyclophanes by Selective ortho‐Halogenation with Pd‐Catalyzed C–H Activation
作者： Joshua J. P. Kramer , Ceylan Yildiz , Martin Nieger , Stefan Bräse
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摘要: A palladium-catalyzed protocol for the halogenation of [2.2]paracyclophanes by C–H activation is described, and ortho selectivity achieved with an O-methyloxime directing group. Bromination iodination sterically demanding [2.2]paracyclophane proceed in good yields inexpensive readily available N-halosuccinimides. Deprotection O-methyloximes ortho-halogenated aldehydes as attractive intermediates modular synthesis 4,5-disubstituted [2.2]paracyclophanes. The synthetic value this was demonstrated exemplary conversions carbaldehyde halogen site. Additionally, early stage resolution subsequent bromination/deprotection provides brominated aldehyde enantiopure form.
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