Enantioselective, Catalytic Vicinal Difluorination of Alkenes.
Authors of this article are:
Scheidt F Schäfer M Sarie J Daniliuc C Molloy J Gilmour R.
A summary of the article is shown below:
The enantioselective, catalytic vicinal difluorination of alkenes is reported via I(I)/I(III) catalysis using a novel, C2-symmetric resorcinol derivative. Catalyst turnover via in situ generation of an ArI(III)F2 species is enabled by Selectfluor® oxidation and addition of an inexpensive HF•amine complex. The HF•amine ratio employed in this Umpolung 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 94:6 e.r.). An achiral variant of the reaction is also presented using p-TolI (up to >95% yield).
Check out the article’s website on Pubmed for more information:
This article is a good source of information and a good way to become familiar with topics such as: Brønsted acid;Catalysis;difluorination;enantioselectivity;iodine.
Categories: Science News