Triflates cross-coupling, heteroaromatics

Although difluoroenoxysilanes are typical nucleophiles, they can also react with other nucleophiles via their oxidation into radical cations. The oxidative homocoupling and the cross-coupling with heteroaromatics and alcohols proceeds very well in the presence of Cu triflate as the oxidizing reagent (Figure 2.24). " ... 

Various aryl, alkenyl and even alkylborane reagents of different reactivity can be used for coupling with aryl, alkenyl, alkynyl and some alkyl halides, offering very useful synthetic methods. The cross-coupling of aryl and heteroarylboronic acids with aryl and heterocyclic halides and triflates provide useful synthetic routes to various aromatic and heteroaromatic derivatives. Sometimes, the reaction proceeds in the... 

Chemoselective Stille cross-coupling of 2 -triflato-(Z)-2-stannyl-2-butenanilides 5.42 with aromatic or heteroaromatic iodides gives the 2 -triflato-(Z)-2-aryl(or heteroaryl)-2-butenanilides 5.43 in high yield. The faster rate of the oxidative addition of iodides compared to triflates to Pd(0) is the origin of chemoselectivity observed in this reaction. ... 

Pd-catalyzed Miyaura boration Pd-catalyzed cross-coupling of aromatic and heteroaromatic halides or triflates with tetraalkoxydiboron compounds to give arylboronic and heteroarylboronic esters. 296... 

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