In the presence of 5-10 mol% Cp*RuCI(cod), 1,6- and 1,7-diynes were allowed to react with an ethynylboronate at ambient temperature to give rise to bicyclic arylboronates in 64-93% isolated yields. 1,6-Diynes bearing a boronate terminal also underwent cycloaddition with monoalkynes to give the corresponding bicyclic arylboronates. (c) 2006 Elsevier Ltd. All rights reserved.
Intramolecular [2+2+1] Cycloadditions with (Cyclobutadiene)tricarbonyliron