title: Organocatalytic 1,4-Addition Reaction of 2-Formyl(thio)esters to Vinylketones: An Efficient Access to Acyclic Chiral Building Blocks with a Quaternary Carbon Stereocenter.
abstract: 2-Formyl(thio)esters were utilized as pronucleophiles to obtain less-accessible acyclic chiral building blocks bearing versatile functional groups on a quaternary carbon atom for enantioselective 1,4-addition to vinylketones. To achieve high enantioselectivity in the present 1,4-addition reaction, thiourea-tertiary amines containing a bulky chiral backbone were developed as catalysts, and several derivatizations of the products were performed to demonstrate the synthetic utility of the products.
authors.affiliation: Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan).
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Tatsumi
authors.affiliation: Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan). misaki@sci.u-hyogo.ac.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Misaki
authors.affiliation: Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan).
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugimura
keywords: Michael addition; aldehydes; asymmetric catalysis; enones; organocatalysis