A novel and easily accessible metal-free catalytic system, an
in situ generated BINOL-phosphate-derived silicon Lewis acid, has
been described for the [3+2] cycloaddition
of N-benzoylhydrazone to cyclopentadiene
to afford a cycloadduct in high diastereomeric ratio of
95:5 (syn/anti)
and enantiomeric excess of 89%. These results provide insights
in the future design and development of highly active and enantioselective
silicon Lewis acids for this and other cycloaddition types.
cycloaddition - silicon - hydrazones - Lewis
acids - nitrogen heterocycles
