title: GaCl3-catalyzed allenyne cycloisomerizations to allenenes.
abstract: Cycloisomerizations of allenynes to allenenes have been studied in the presence of catalytic amounts of [Au(PPh3)]SbF6 in dichloromethane or GaCl3 in toluene. Both catalytic systems are quite effective for terminal 1,6-allenynes. However, they showed different reactivities toward allenynes with di-substituents at the allenic terminal carbon. For the GaCl3-catalyzed reactions, allenenes were obtained in reasonable to high yields. However, for a Au(I)-catalyzed reaction, a triene was obtained in a poor yield. Thus, GaCl3 serves as an effective catalyst for the cycloisomerization of allenynes bearing a terminal alkyne to give cyclic allenenes in reasonable to high yields.
authors.affiliation: Intelligent Textile System Research Center and Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea.
authors.forename: Sang Ick
authors.initials: SI
authors.lastname: Lee
authors.forename: So Hee
authors.initials: SH
authors.lastname: Sim
authors.forename: Soo Min
authors.initials: SM
authors.lastname: Kim
authors.forename: Kwang
authors.initials: K
authors.lastname: Kim
authors.forename: Young Keun
authors.initials: YK
authors.lastname: Chung