Appling the photo-benzylation of isoquinoline with benzyltrifluoroborate, an extremely facile method for the construction of a pavine alkaloid skeleton was developed. When 3-methoxybenzylboron reagents were employed to the reaction, it was found that not only benzylation but also the subsequent intramolecular cyclization proceeded smoothly without any additional acidic catalyst. © 2020 The Chemical Society of Japan