Department of Chemistry and Chemical Biology , Harvard University , Cambridge , Massachusetts 02138 , United States.
Org Lett. 2019 Jul 5;21(13):4919-4923. doi: 10.1021/acs.orglett.9b00938. Epub 2019 Apr 9.
The enantio- and diastereoselective synthesis of 1,2-difluorides via chiral aryl iodide-catalyzed difluorination of cinnamamides is reported. The method uses HF-pyridine as a fluoride source and mCPBA as a stoichiometric oxidant to turn over catalyst, and affords compounds containing vicinal, fluoride-bearing stereocenters. Selectivity for 1,2-difluorination versus a rearrangement pathway resulting in 1,1-difluorination is enforced through anchimeric assistance from a N- tert-butyl amide substituent.
本文报道了通过手性芳基碘催化肉桂酰胺的二氟化反应,实现 1,2-二氟化物的对映选择性和非对映选择性合成。该方法使用 HF-吡啶作为氟源,mCPBA 作为计量氧化剂来实现催化剂的转化,并提供了含有相邻、含氟立体中心的化合物。通过 N-叔丁基酰胺取代基的邻基协助,强制选择 1,2-二氟化反应而不是导致 1,1-二氟化反应的重排途径。