The Pd-catalyzed C-H alkylation of ortho-methyl-substituted aromatic amides with maleimide occurs preferentially at the ortho-methyl C-H bond over the ortho-C-H bond.
Qiyuan HeYusuke AnoNaoto ChataniPublished in: Chemical communications (Cambridge, England) (2019)
The reaction of ortho-methyl-substituted aromatic amides with maleimides in the presence of Pd(OAc)2 and AgOAc results in C-H alkylation at the ortho-methyl C-H bond. DFT calculations indicate that the formation of a five-membered palladacycle is a kinetically favorable step, but the insertion of the maleimide into the six-membered palladacycle is energetically favored.