1,3-Dipolar cycloaddition of 4-platinumisochromenyliums with an olefin and tandem insertion into benzylic C-H bonds

Isochromenylium-4-ylplatinum(II) species, generated from 1-(2-alkynylphenyl)hex-5-en-1-ones and Pt(II), reacted with a pendant olefin via [3+2] cycloaddition to form tetracyclic Pt-carbene complexes, which underwent C-H insertion with a benzyloxy group at delta or epsilon positions to give highly complex polycycles, which are otherwise hard to access.Financial support was provided by a grant from the National Research Foundation of Korea (NRF 3 201200000000953)