Rachel E. M. Brooner, Bradley D. Robertson, R. Widenhoefer
Oct 29, 2014
Citations
0
Influential Citations
27
Citations
Journal
Organometallics
Abstract
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 Bronsted 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 Bronsted acid catalyzed 1,3-hydrogen migration outside the coordination sphere of gold.