title: Alternate mode of palladium-catalyzed alkynyliminium ion cyclizations affording stereodefined N-alkyl-3-alkylidenepyrrolidines.
abstract: Pd/P(c-C6H11)3-catalyzed alkynyliminium ion cyclization in the presence of organoboronic acids affords stereodefined N-alkyl-3-alkylidenepyrrolidines. The distinctive cis-selective addition of the boronic acids and the iminium ions across the alkyne would result from favored 5-exo- or 6-exo-dig cyclization through oxidative addition of the formaldiminium ions to Pd(0).
authors.affiliation: Graduate School of Pharmaceutical Sciences, Tohoku University , Aramaki-aza aoba 6-3, Aoba-ku, Sendai 980-8578, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Tsukamoto
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Shiraishi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Doi
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D001897:Boronic Acids; D007097:Imines; D011759:Pyrrolidines; D010165:Palladium