Synthesis of dihydroisoquinolinone-4-methylboronic esters from N-allylcarboxamides and B₂(Pin)₂ via domino Heck/borylation approach is reported. A quinoxaline-based NHC-palladacycle [Pd(C∧C:)PPh₃Cl], which has been structurally characterized, is used as a catalyst. The scope of the substrate with a wide range of substituents is explored. In addition to the synthesis of title compounds, a few examples of methylboronic esters of indoline and benzofuran motifs have also been prepared using the same protocol.