Trimerization of alkynes to aromatic compounds: J. Am. Chem. Soc., 84, 2329 (1962); Synthesis, 659 (1986). Review: Acc. Chem. Res., 9, 93 (1976). Cyclopropanation of various allylic alcohols, ethers and amines by diazomethane: Synthesis, 246 (1990). In the presence of a tert-amine, catalyzes the cyclization of 3- and 4-alkynoic acids to unsaturated lactones in high yield: Tetrahedron Lett., 25, 5323 (1984). Catalyst for the Ag2O promoted Suzuki coupling of arylboronic acids with sensitive halides: Org. Synth., 75, 69 (1997); In combination with N,N-dimethylglycine, forms a highly active phosphine-free catalyst system for the Heck reaction of aryl bromides: Tetrahedron Lett., 39, 8449 (1998). In combination with CuI, terminal alkynes couple with vinyl chlorides to give conjugated enynes in high yield: Tetrahedron Lett., 32, 6109 (1991). This has been exploited in a synthesis of lipoxin B4: Synlett, 217 (1993), and of (Z)- and (E)-enediynes from the isomeric 1,2-dichloroethylenes: Tetrahedron Lett., 35, 3543 (1994). In combination with Ti(O-i-Pr)4, promotes the symmetrical coupling of arylsulfonyl chlorides to biaryls: Chem. Lett., 459 (1990). For a brief feature on uses in synthesis, see: Synlett, 1449 (2006).