Allylboration of functionalized isoquinolines

Functionalized isoquinolines react with triallylborane to produce 1,3-diallylated 1,2,3,4-tetrahydroisoquinolines 1–8 with excellent chemo- and stereoselectivity. In these conditions 4-bromoisoquinoline was converted into tricyclic aziridine 10. Synthesis of monoallylated tetrahydroisoquinolines using allyldipropylborane and reduction with NaBH4 was also developed.