Synthesis of substituted quinolines using the dianion addition of N-Boc-anilines and α-tolylsulfonyl-α,β-unsaturated ketones

Article abstract of DOI:10.1021/jo0203387

A short and versatile synthesis of substituted quinolines is provided. Alkylation of sodium tolylsulfinate with bromomethyl- or chloromethyl ketones generates β-keto sulfones. Knoevenagel condensation of the β-keto sulfones with an aldehyde provides α-tolylsulfonyl-α,β-unsaturated ketones. Michael addition of the dianion of N-Boc-anilines in the presence of CuCN and LiCl with the unsaturated ketone generates a 1,4-adduct, which after deprotection of the Boc group and thermal elimination of the tolyl sulfone provides the quinoline.