title: Metal-catalyzed annulation reactions for π-conjugated polycycles.
abstract: The progress of the metal-catalyzed annulation reactions toward construction of various π-conjugated polycyclic cores with high conjugation extension is described. This article gives a brief overview of various annulation reactions promoted by metal catalysts including C-H bond functionalization, [2+2+2] cycloaddition, cascade processes, ring closing metathesis, electrophilic aromatization, and various cross-coupling reactions. A variety of conjugated polycycles with planar, bowl-shaped, and helical structures have been constructed in high efficiency and selectivity.
authors.affiliation: WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577 (Japan). tjin@m.tohoku.ac.jp.
authors.forename: Tienan
authors.initials: T
authors.lastname: Jin
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.forename: Naoki
authors.initials: N
authors.lastname: Asao
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Yamamoto
keywords: annulation; homogeneous catalysis; pi conjugation; polycycles; transition metals