One‐Pot Sandmeyer Trifluoromethylation and Trifluoromethylthiolation

Abstract

Practical one-pot procedures were developed for both Sandmeyer-type trifluoromethylations and trifluoromethylthiolations. Starting from broadly available (hetero)aromatic amines, various benzotrifluorides were synthesized in high yields via in situ diazotization and copper-mediated trifluoromethylation using the inexpensive Ruppert-Prakash trifluoromethylating reagent. In the presence of sodium thiocyanate as a sulfur source, aryl trifluoromethyl thioethers are exclusively formed.

Trifluoromethylselenolation of Aryldiazonium Salts: A Mild and Convenient Copper‐Catalyzed Procedure for the Introduction of the SeCF3Group

“…Therefore, we wondered whether ac opper-catalyzed Sandmeyer reaction for the introductiono fs elenium [10] followed by ar eaction with the Ruppert-Prakash reagent would give the trifluoromethylseleno-functionalized compounds. [11,12] This would in principle allow the preparation of different trifluoromethyl aryl selenides from anilines.Various reactions for the introductiono fs eleniuma toms are highly dependent on the selenium source. Polymeric "grey" selenium shows very poor reactivity and often side products are formed.…”

“…Therefore, we wondered whether ac opper-catalyzed Sandmeyer reaction for the introductiono fs elenium [10] followed by ar eaction with the Ruppert-Prakash reagent would give the trifluoromethylseleno-functionalized compounds. [11,12] This would in principle allow the preparation of different trifluoromethyl aryl selenides from anilines.…”

Rapid and Efficient Synthesis of [11C]Trifluoromethylarenes from Primary Aromatic Amines and [11C]CuCF3

“…Our yields from [ 11 C]fluoroform, where comparable, approximately aligns with those obtained by Danoun et al ( 43 ) for the macroscale Sandmeyer-type trifluoromethylation of aryldiazonium tetrafluoroborates with trifluoromethyltrimethylsilane in the presence of copper(I) thiocyanate (nine examples), and similarly with those observed by Bayarmagnai et al (six examples). 44 Based on radical trapping experiments, 39 it is generally presumed that this type of Sandmeyer reaction proceeds through a radical pathway. 45 In this study, the diazotization of the primary aromatic amine, followed by the dissociation of the diazonium species (I), may yield a radical intermediate (II).…”

Sandmeyer Trifluoromethylation

“…After stirring for 30 minutes at room temperature, the reaction mixture is added to a suspension of CuSCN (0.5 equiv), TMSCF 3 (1.5 equiv) and Cs 2 CO 3 (1.5 equiv) in acetonitrile, and stirring is continued for 12 hours. 12 This one-pot process gives comparable, sometimes even higher yields than the two-step protocol (Table 1, Process B).…”