Annulation of Anilides or Benzamides

Shibata and Tanaka reported that the reaction of acetanilides with 2c can be promoted by [Cp RhCl2]2/AgSbF6 [Cp = l,3-bis(ethoxycarbonyl)-2,4,5-trimethylcyclopentadienyl] more efficiently than [Cp RhCl2]2/AgSbF6 [30], 

Ar = Ph, 92% yield Ar = 4-MeCgH4, 98% yield Ar = 4-MeOCgH4, 92% yield Ar = 4-ClCgH4, 83% yield Ar = 2-thienyl, 78% yield 

R = COjEt, 82% yield R = TMS, 76% yield R = CHjCOjMe, 79% yield R = CH20TBS, 81% yield R = CH2NPhth, 77% yield 

At = Ph, 75% yield At = 4-MeOC6H4, 73% yield At = 4-i-BuC6H4, 68% yield At = 4-CIC6H4, 72% yield 

In similar reactions of acrylamides with unsymmetrical alkynes, Hyster and Rovis used [Cp Rh(MeCN)3][SbF6]2 as a catalyst to improve the regioselectivity (Cp = 1,3-di-f-butylcyclopentadienyl) [44]. 

---