Through the incorporation of a silicon atom to an aryl carboxylic ester substrate, the resulting C-Si bond can be activated via the addition of a carbene catalyst on a remote site. This strategy allows for efficient functionalization of the benzylic sp-carbons of aryl carboxylic esters.

Carbene-catalyzed enantioselective addition of benzylic carbon to unsaturated acyl azolium for rapid synthesis of pyrrolo[3,2-c]quinolines

Experimental procedures and spectral data for all new compounds (PDF)Accession Codes CCDC 1960143 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk

A carbene-catalyzed reaction to synthesize a chiral quinazolinone with a new activation mode of an “aniline-like” N–H moiety is disclosed. Addition of the nitrogen atom of diphenyl o-aminobenzaldehydes via NHC activation to imines leads to chiral quinazolinones with high yields and optical purities. The acidity of the N–H moiety was extremely increased through the formation of an acyl azolium intermediate, which was investigated by DFT calculations. Moreover, the chiral quinazolinones were found to have high fluorescence quantum efficiency.