Synthesis Of Aryl Trifluoromethyl Thioethers And Carbamates By Copper-Catalyzed Coupled Reaction

The trifluoromethylthio group (CF3S-), especially as aryl trifluoromethyl thioethers, is important structural unit found in many pharmaceutical and agrochemical products, and key intermediate for trifluoromethyl sulfoxide and sulfone. Numerous impressive progresses for the synthesis of aryl trifluoromethyl thioethers have been available in both academic and industrial laboratories.Most known methods for synthesizing aryl trifluoromethyl thioethers can be divided into three groups:halogen-fluorine exchange reactions, nucleophilicreaction of trifluoromethylthio reagents with aryl halides, boronic acids, or alkynes, nucleophilic or radical reaction of aryl sulfides, disulfides, and so on with trifluoromethylation reagents. However, these transformations are encumbered by significant limitations, for example, the requirement of electron-poor aromatic groups, the use of expensive and/or toxic reagents, and the requirement of preliminary synthesis of the sulfur-containing precursor.In this paper, we synthesized aryl trifluoromethyl thioethers by a practical Cu-mediated oxidative trifiuoromethylthiolation of aryl boronic acids with CF3CO2Na and S8-After screening the reaction parameters, We ensured the optimal reaction conditions:1equiv. CuSCN as the catalyst,1equiv.1,10-phenanthroline (phen) as the ligand,2equiv. Ag2CO3as the oxidant,3equiv. K3PO4, DMF as solvent,0.2mmol aryl boronic acids react with0.6mmol Ss and1.0mmol CFaCONa at130℃for24h, and eighteen aryl trifluoromethyl thioethers were synthesized. This approach uses inexpensive and available Ss and CF3CO2Na as raw materials, and has some advantages such as short synthetic route and commercial available.Carbamates possess a lot of useful properties in the synthesis of phannaeeuticals, agroehemicals and functional materials. The main approach to carbamates in industry is phosgene method, which suffers from drawbacks such as multistep synthesis, using toxic phosgene, and serious corrosion. In the chapter three of this paper, we synthesized quinolin-8-yl carbamates by Cu-catalyzed C-O coupling, taking advantage of8-hydroxyquinoline’s coordination ability toward copper. Four quinolin-8-yl carbamates were synthesized, the isolated yield up to88%. It is a convenient, efficient and atom-economic protocol for the synthesis of carbamates, relatively. Furthermore, we expanded this method to the composition of aromatic esters by radical C-O coupling reaction. The optimal reaction condition is10mol%CuCl,3equiv TBHP,1.4-dioxane as the solvent,0.4mmol8-hydroxyquinoline and1.2mmol aromatic aldehydes at80℃for24h. This procedure can apply to a large scope of substituents and tolerated a range of functional groups.