Practical Photocatalytic Trifluoromethylation and Hydrotrifluoromethylation of Styrenes in Batch and Flow
作者:Natan J. W. Straathof、Sten E. Cramer、Volker Hessel、Timothy Noël
DOI:10.1002/anie.201608297
日期:2016.12.12
represent a challenging class of substrates for current radical trifluoromethylation and hydrotrifluoromethylation methods due to a myriad of potential side reactions. Herein, we describe the development of mild, selective and broadly applicable photocatalytic trifluoromethylation and hydrotrifluoromethylation protocols for these challenging substrates. The methods use fac‐Ir(ppy)3, visible light and
A simple synthesis of 3,3,3-trifluoropropenyl compounds by means of the TBAF-mediated Horner reaction is described. The reagent, 2,2,2-trifluoroethyldiphenylphosphine oxide, was readily prepared either by Arbuzov reaction of ethyl diphenylphosphinite with 2,2,2-trifluoroethyl iodide or by treating chlorodiphenylphosphine with trifluoroacetic acid and water. Treatment of the phosphine oxide with aromatic
A visible-light-induced decarboxylative trifluoromethylation of alpha,beta-unsaturatedcarboxylicacids, which uses the Togni reagent as the CF3 source is disclosed. The corresponding trifluoromethylated alkenes were obtained in moderate to high yields with excellent functional group tolerance at ambient temperature. Preliminary mechanistic analyses suggest a radical-type mechanism.
An efficient decarboxylative trifluoromethylation of α,β-unsaturated carboxylic acids using the Langlois reagent as a trifluoromethyl precursor has been achieved by an electro-oxidative strategy. Under catalyst-free and external oxidant-free electrolysis conditions, a series of Cvinyl-CF3 compounds are obtained with a high regioselectivity in good yields. The successful trapping of the CF3 radical