Preparation and reaction of metallacyclic compounds have attracted increasing interest in recent years, since many synthetically important transition-metal-assisted reactions proceed via metallacyclic intermediates. Compared with a large number of reports on 5-membered metallacycles, there are only a few reports on 6-membered metallacycles. Because of the potential application of 6-membered metallacycles, a review is given about the preparative methods of six-membered metallacycles developed in our group as well as in other groups.

Key words: six-membered metallacycle, metallacyclohexane, metallacyclohexene, metallacyclohexadiene, metallabenzene