Bronsted acid-catalyzed insertion of aryldiazoacetates to sp2 Carbon-CHO bond:: Facile construction of chiral all-carbon quaternary center

Aryldiazoacetates could be formally inserted into the carbon-carbon bond of the Bronsted acid-activated aromatic and alpha,beta-unsaturated aldehydes. Use of phenylmenthyl esters allowed the asymmetric induction at the inserted all-carbon quaternary carbon center with the excellent stereoselectivities.