title: Gold(I) and Palladium(II) Complexes of 1,3,4-Trisubstituted 1,2,3-Triazol-5-ylidene "Click" Carbenes: Systematic Study of the Electronic and Steric Influence on Catalytic Activity.
abstract: The synthesis of a small family of six electronically and sterically modified 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene gold(I) chloride complexes is described. Additionally, the correspondingtrans-[PdBr2(iPr2-bimy)(1,3,4-trisubstituted 1,2,3-triazol-5-ylidene)] complexes are also generated and used to examine the donor strength of the 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene ligands. All compounds have been characterized by1H and13C NMR and IR spectroscopy, high-resolution electrospray mass spectrometry (HR-ESI-MS), and elemental analysis. The molecular structures of four of the gold(I) and four of the palladium(II) complexes were determined using X-ray crystallography. Finally, it is demonstrated that these 1,2,3-triazol-5-ylidene gold(I) chloride complexes (Au(trz)Cl) are able to catalyze the cycloisomerization of 1,6-enynes, in high yield and regioselectivity, as well as the intermolecular direct etherification of allylic alcohols. Exploiting the Au(trz)Cl precatalysts allowed the etherification of allylic alcohols to be carried out under milder conditions, with better yield and regioselectivity than selected commercially available gold(I) catalysts.
authors.affiliation: Department of Chemistry, University of Otago , P.O. Box 56, Dunedin, New Zealand.
authors.forename: James R
authors.initials: JR
authors.lastname: Wright
authors.affiliation: Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University , Edinburgh EH14 4AS, U.K.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Young
authors.affiliation: Department of Chemistry, University of Otago , P.O. Box 56, Dunedin, New Zealand.
authors.forename: Nigel T
authors.initials: NT
authors.lastname: Lucas
authors.affiliation: Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University , Edinburgh EH14 4AS, U.K.
authors.forename: Ai-Lan
authors.initials: AL
authors.lastname: Lee
authors.affiliation: Department of Chemistry, University of Otago , P.O. Box 56, Dunedin, New Zealand.
authors.forename: James D
authors.initials: JD
authors.lastname: Crowley