Recyclable Pd(II)complex catalyzed oxidative sp2 CH bond acylation of 2-aryl pyridines with toluene derivatives

Recent Advances in Cross‐Dehydrogenative Couplings (CDC) of C−H Bond in Aqueous Media

“…Mandapati and co‐workers [32] reported an effective aroylation reaction by using a recyclable Pd complex and TBHP as catalyst and oxidant starting from 2‐phenyl pyridines with toluene derivatives in water [Eq. (17)].…”

“…This process involved acylation of anilines, palladiumcatalyzed cross-dehydrogenative coupling of the formed anilides, and the hydrolytic cleavage [Eq. (32)]. In this three-step synthesis, the acetyl group could either protect the amino group or activate the CÀ H bond as an ortho-directing group.…”

Cross-dehydrogenative coupling involving benzylic and allylic C–H bonds

“…38 Next, the oxidative addition of the in-situ formed acyl radical to the palladacycle generates either a Pd(IV) 39 The CDC coupling of 2-aryl pyridines with toluene derivatives was also recently reported by Mandapati, Parvathaneni and coworkers, using a Pd(II) complex anchored to a polystyrene (PS) resin (Scheme 21a). 41 The catalyst used was very stable and easy to recover and reuse in four consecutive cycles, without affecting its activity or selectivity. The reaction was performed in the absence of solvents, using on-water conditions, very low palladium loading and exhibiting a broad substrate scope.…”

Pd(II)-Catalyzed C-H Acylation of (Hetero)arenes—Recent Advances

“…However, it has been shown that a recyclable heterogeneous palladium complex under on-water conditions, using toluenes as the acyl source ( Scheme 2 b), can replace homogeneous catalysts. Polymer supported furan-2-ylmethanamine complex is stable and could be reused for 5 cycles without loss of efficiency [ 11 ]. α-Oxoacids have been also used as the acyl source in decarboxylative acylation reactions in the presence of silver salts [ 12 ].…”