Gold chemistry is somewhat weird.
Gold is the least electropositive metal, with an electronegativity (2.54) virtually the same as that of carbon (2.55). Partly as a result of that, the Au-C bond is strong and apolar, atypical for organometallic compounds. Au(III) is iso-electronic with Pt(II) but very different in its chemistry. It is easily reduced to Au(I) or Au metal. Gold compounds are good at promoting complicated rearrangements of carbon skeletons. Au(II) also appears to have some relevance in catalysis.
We are beginning to explore, in collaboration with the group of Manfred Bochmann, mechanistic aspects of organogold chemistry. For relevant papers, see numbers 168, 164 and 160 of my publication list.