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8. Enantioselective, Catalytic Vicinal Difluorination of Alkenes.

F. Scheidt, M. Schäfer, J. C. Sarie, C. G. Daniliuc, J. J. Molloy, R. Gilmour – 2018

The enantioselective, catalytic vicinal difluorination of alkenes is reported by II/IIII catalysis using a novel, C2-symmetric resorcinol derivative. Catalyst turnover via in situ generation of an ArIIIIF2 species is enabled by Selectfluor oxidation and addition of an inexpensive HF–amine complex. The HF:amine ratio employed in this process provides a handle for regioselective orthogonality as a function of Brønsted acidity. Selectivity reversal from the 1,1-difluorination pathway (geminal) to the desired 1,2-difluorination (vicinal) is disclosed (>20:1 in both directions). Validation with electron deficient styrenes facilitates generation of chiral bioisosteres of the venerable CF3 unit that is pervasive in drug discovery (20 examples, up to 94:06 e.r.). An achiral variant of the reaction is also presented using p-TolI (up to >95 % yield).

Title
8. Enantioselective, Catalytic Vicinal Difluorination of Alkenes.
Author
F. Scheidt, M. Schäfer, J. C. Sarie, C. G. Daniliuc, J. J. Molloy, R. Gilmour
Date
2018
Identifier
DOI: 10.1002/anie.201810328
Source(s)
Citation
Angew. Chem. Int. Ed. 2018, 57, 16431–16435
Type
Text