B(C₆F₅)₃‐Catalyzed 1,4‐Allylation of Azadienes with Allyltrimethylsilanes

Abstract

A metal‐free 1,4‐allylation of azadienes with allyltrimethylsilanes catalyzed by B(C6F5)3 has been developed. The high Lewis acidity, good thermal stability, and good hydrolytic stability of the catalyst make this reaction efficient and operationally simple. In contrast to the previously reported 1,2‐allylation of α,β‐unsaturated imines, the 1,4‐allylation of azadienes is described here for the first time. Benzofuran‐, indene‐, dihydronaphthalene‐, chromene‐, and benzothiophene‐based allyl arylmethanes have been obtained in up to 95 % yield.

Copper-Catalyzed Enantioselective 1,2-Allylation of Azadienes with Allylboronates

“…Surprisingly, very few studies on its use in the catalytic addition of aurone-derived azadienes have been described. Until now, only Wang’s group reported an efficient 1,4-conjugate addition reaction of azadienes with allyltrimethylsilanes catalyzed by Lewis acid B­(C 6 F 5 ) 3 (Scheme b) . The 1,2-allylation of aurone-derived azadienes, however, has not yet been reported.…”