title: Boron Tribromide-Assisted Chiral Phosphoric Acid Catalyst for a Highly Enantioselective Diels-Alder Reaction of 1,2-Dihydropyridines.
abstract: BBr3-chiral phosphoric acid complexes are highly effective and practical Lewis acid-assisted Brønsted acid (LBA) catalysts for promoting the enantioselective Diels-Alder (DA) reaction of α-substituted acroleins and α-CF3 acrylate. In particular, the DA reaction of α-substituted acroleins with 1,2-dihydropyridines gave the corresponding optically active isoquinuclidines with high enantioselectivities. Moreover, transformations to the key intermediates of indole alkaloids, catharanthine and allocatharanthine, are demonstrated.
authors.affiliation: Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Hatano
authors.affiliation: Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Atsuto
authors.initials: A
authors.lastname: Izumiseki
authors.affiliation: Department of Chemistry, Aichi University of Education , Igaya-cho, Kariya 448-8542, Japan.
authors.forename: Matsujiro
authors.initials: M
authors.lastname: Akakura
authors.affiliation: Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Ishihara