In a novel disconnection of isoquinoline ring synthesis at the C7-C8/C4a-C8a bonds, these bonds can be formed by a [4+2] cycloaddition between thiophene S, S-dioxide and alkynes. With a subsequent C-H arylation of the resulting hexaarylisoquino-line at the C3 position, the synthesis of a fully substituted isoquinoline has been achieved.