The Enantioselective Pauson-Khand Reaction - The Pauson-Khand Reaction - page 174

6.7 Conclusion
A general catalytic methodology for the enantioselective PKR has not yet been developed.
However, research efforts in this area have proved invaluable, not only for revealing the
difficulty of this endeavor, but has also for providing enlightening mechanistic insight that
should help pave the way for asymmetric PKRs in the future. Nonetheless, high enantios-
electivities have been achieved in a few intramolecular PKRs using catalytic amounts of
BINAP as ligand. Moreover, stoichiometric reaction of bidentate (P,S)-ligands has proven
to be a reliable procedure, providing ready access to useful synthetic intermediates. The PK
cycloadduct 3i (formed by reaction of trimethylsilylacetylene and norbornadiene) has re-
cently been used to synthesize biologically active compounds, including the phytoprostanes
dPPJ 1 -I and dPPJ 1 -II and the carbanucleosides Carbovir and Abacavir, underscoring its
value as a chiral starting material.
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