The cationic gold phosphine complex [{PCy2 (o-biphenyl)}Au(NCMe)](+) SbF6 (-) (Cy=cyclohexyl) catalyzes the intermolecular, anti-Markovnikov hydroamination reaction of monosubstituted and cis- and trans-disubstituted alkylidenecyclopropanes (ACPs) with imidazolidin-2-ones and other nucleophiles. This reaction forms 1-cyclopropyl alkylamine derivatives in high yield and with high regio- and diastereoselectivity. NMR spectroscopic analysis of gold π-ACP complexes and control experiments point to the sp hybridization of the ACP internal alkene carbon atom as controlling the regiochemistry of the ACP hydroamination reaction.

The gold 7-phenylbicyclo[3.2.0]hept-1(7)-ene complex 1 is generated as an intermediate in the gold-catalyzed cycloisomerization of 7-phenyl 1,6-enyne 2 to 7-phenylbicyclo[3.2.0]hept-1(7)-ene 3. We have investigated the kinetics of the isomerization of 1 via formal 1,3-hydrogen migration to form the corresponding gold 6-phenylbicyclo[3.2.0]hept-6-ene complex 4 to obtain direct experimental information regarding the mechanism by which 1 evolves into products. These experiments were in accord with conversion of 1 to 4 through a hidden Brønsted acid catalyzed pathway that occurred outside the coordination sphere of gold. Similarly, in situ spectroscopic analysis of the catalytic cycloisomerization of enyne 2 was consistent with a mechanism involving sequential gold-catalyzed cycloaddition followed by Brønsted acid catalyzed 1,3-hydrogen migration outside the coordination sphere of gold.

The first asymmetric total synthesis of the marine natural product apratoxin D, a highly potent inhibitor of H-460 human lung cancer cell growth (IC(50) value of 2.6 nM), is described. Asymmetric N-amino cyclic carbamate (ACC) α,α-bisalkylation was utilized to establish the isolated C-37 methyl group with excellent selectivity. Other key asymmetric transformations employed were an Evans syn-aldol and a Paterson anti-aldol, both of which also proceeded with excellent stereoselectivity.