Studying Regioisomer Formation in the Pd‐Catalyzed Fluorination of Cyclic Vinyl Triflates: Evidence for in situ Ligand Modification
Name
Angew Chem Int Ed - 2023 - Ye - Studying Regioisomer Formation in the Pd‐Catalyzed Fluorination of Cyclic Vinyl Triflates .pdf
Description
Published version
Size
8.02 MB
Format
Adobe PDF
Checksum (MD5)
d2e3fdc18b22c33ef75823142c836c6b
Author(s)
Ye, Yuxuan
Kim, Seoung‐Tae
King, Ryan P
Baik, Mu‐Hyun
Buchwald, Stephen L
Date Issued
February 12, 2023
Journal
Angewandte Chemie International Edition
Publisher
Wiley
Citation
Y.Ye, S.-T.Kim, R. P.King, M.-H.Baik, S. L.Buchwald, Angew. Chem. Int. Ed.2023, 62, e202300109; Angew. Chem.2023, 135, e202300109.
Version
Final published version
Abstract
Pd-catalyzed nucleophilic fluorination reactions are important methods for the synthesis of fluoroarenes and fluoroalkenes. However, these reactions can generate a mixture of regioisomeric products that are often difficult to separate. While investigating the Pd-catalyzed fluorination of cyclic vinyl triflates, we observed that the addition of a substoichiometric quantity of TESCF3 significantly improved the regioselectivity of the reaction. Herein, we report a combined experimental and computational study on the mechanism of this transformation focusing on the role of TESCF3. The poor regioselectivity of the reaction in the absence of additives results from the formation of LPd-cyclohexyne complexes (L=biaryl monophosphine ligand). When TESCF3 is added to the reaction mixture, the generation of the Pd-cyclohexyne complexes is diminished by an unexpected pathway involving the dearomatization of the ligand by nucleophilic attack from a trifluoromethyl anion (CF3−).
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Creative Commons Attribution-NonCommercial-NoDerivatives
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DOI of Published Version
10.1002/anie.202300109
