A convenient, transition metal-free synthesis of difluoromethyl selenoethers from organic selenocyanates and TMSCF2H

An efficient and transition metal-free method for the synthesis of aryl or alkyl difluoromethyl selenides (RSeCF2H) from the corresponding selenocyanates (RSeCN) and TMSCF2H/t-BuOK is described. The reaction performed in THE at 0 degrees C for 24 h or at room temperature for 6 h supplied a series of RSeCF2H in good to high yields. The successful preparation of difluoromethylselenolated sulfadimethoxine derivative and the scaled-up synthesis of 1-benzyl-5-((difluoromethyl)selanyl)indoline, as examples, suggested good practicability of this method. Advantages of the reaction include mild reaction conditions, good functional group tolerance, a wide range of substrates, and high efficiency. This protocol offered a number of novel difluoromethyl selenoethers, which would accelerate use of such compounds in the areas of life science. (C) 2018 Elsevier Ltd. All rights reserved.