Chlorodifluoromethyl group was introduced into aromatic rings using bis(chlorodifluoroacetyl) peroxide which was readily prepared from corresponding acid anhydride with 30% hydrogen peroxide, and the chlorine was successively replaced by hydrogen or allyl group in excellent yields under radical conditions.
Visible Light‐Mediated Metal‐Free Chlorodifluoromethylation of Arenes and Heteroarenes by a Hypervalent Iodine EDA Complex
作者:Daniel Lin、Vinayak Krishnamurti、G. K. Surya Prakash
DOI:10.1002/ejoc.202200607
日期:2022.9.20
A visible light-mediated electron donor–acceptor complex enabling direct chlorodifluoromethylation of (hetero)arenes is described. This method provides the privileged moiety with mild conditions across a broad range of functional groups and bioactive scaffolds. Post-functionalization reactions and key control experiments are reported as well. The core EDAcomplex is studied spectroscopically, enabling
The selective fluorination by successive Cl/F exchanges of alpha alpha alpha-trichlorotoluene substituted or not by a chlorine atom was studied in the presence of HF as the fluorin long agent The influence of the presence of a catalyst or a basic solvent (such as dioxane pyridine tributylphosphate) in order to control the fluorination was also investigated In mild conditions (50 C and after 1 h of reaction) HF in excess was required in order to obtained the trifluoromethylation by Cl/F exchanges The presence of SbCl5 in small amount activated the Cl/F exchanges and only a stoichiometric amount of HF was required whatever the chlorinated molecules Selective mono and difluorination could be obtained by using basic solvents (C) 2010 Elsevier B V All rights reserved
Rozen Shlomo, Mishani Eyal, J. Chem. Soc. Chem. Commun, (1994) N 18, S 2081