1,2-(Bis)trifluoromethylation of Arylalkynes Using the Copper Complex
A mild and efficient copper-mediated visible light promoted method towards 1,2-(bis)trifluoromethylated styrene derivatives to create E-hexafluorobutenes has been reported. The active trifluoromethylating agent (bpy)Cu(CF3)3 is bench stable and easily prepared from tetrabutylammonium tetrakis(trifluoromethyl)cuprate(III) [T3374] and 2,2'-bipyridyl [B0468]. While it has been known that (bpy)Cu(CF3)3 facilitates single trifluoromethylation it has been demonstrated that it can also add two trifluormethyl units.
N-(Trimethylsilyl)bis(trifluoromethanesulfonyl)imide [T2392] is an analogue of, TMSOTf and TMSN(SO2F)2, which has a very low electron density on its silicon atom and acts as a powerful Lewis acid catalyst in various reactions. For example, the Diels-Alder reaction using acrylates as dienophiles affords the corresponding addition products in high yields under mild conditions.
The Corey-Fuchs reaction is a two-step reaction sequence used to convert aldehydes to terminal alkynes . The intermediate 1,1-dibromoalkene is produced from aldehydes, carbon tetrabromide [T0038] and triphenylphosphine [T0519] during the reaction sequence and can be isolated. This is then converted to the alkyne following the addition of a strong base such as butyllithium.