Asymmetric Cycloaddition Reactions of Aryne Intermediates with a Chiral Carbon-Carbon Axis: Syntheses of Axially Chiral Biaryl Compounds

An asymmetric synthesis via an axially chiral arylaryne intermediate was developed. A cycloaddition reaction with various arynophiles was used to obtain chiral biaryl compounds while preserving the enantiomeric excess (ee) of a precursor even though the reaction proceeds through an arylaryne intermediate, whose ee decreases on a time-dependent basis. High chiral transfer from a precursor to a product was observed not only at low temperature (-78 degrees C) but also at room temperature.