Highly Enantioselective Catalytic Pauson-Khand Type Formation of Bicyclk Cyclopentenones

摘要

The transition-metal promoted cyclocondensation of an alkyne, alkene, and carbon monoxide (the Pauson-Khand reaction when cobalt complexes are employed) has emerged as a highly convergent method for the synthesis of cyclopentenones from readily available starting materials. Many advances relating to this methodology have been reported recently, including the development of cyclizatiohs employing a catalytic amount of the transition-metal complex. One major goal which has remained elusive is the development of a catalytic asymmetric variant of these cyclizations. We report here the first successful realization of this goal.