title: Copper-Catalyzed Diastereoselective Addition of Diborylmethane to N-tert-Butanesulfinyl Aldimines: Synthesis of β-Aminoboronates.
abstract: We have developed a highly chemo- and diastereoselective alkylation of N-tert-butanesulfinyl aldimines with diborylmethane. Whereas the addition of diborylmethane under metal-free conditions shows poor diastereoselectivity, the use of a copper catalyst and a bidentate phosphine ligand significantly enhances the diastereoselectivity, providing chiral β-aminoboronates in good yields. On the basis of the stereochemical outcome, we propose that the reaction likely proceeds via a boron-chelating six-membered chairlike transition state.
authors.affiliation: Department of Chemistry and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH) , Pohang, 790-784, Republic of Korea.
authors.forename: Jinyoung
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Chemistry and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH) , Pohang, 790-784, Republic of Korea.
authors.forename: Yeosan
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Chemistry and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH) , Pohang, 790-784, Republic of Korea.
authors.forename: Junghoon
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Chemistry and Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH) , Pohang, 790-784, Republic of Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Cho