title: Trans-selective rhodium catalysed conjugate addition of organoboron reagents to dihydropyranones.
abstract: The selective synthesis of 2,6-trans-tetrahydropyran derivatives employing the rhodium catalysed addition of organoboron reagents to dihydropyranone templates, derived from a zinc-catalysed hetero-Diels-Alder reaction, is reported. The addition of both arylboronic acids and potassium alkenyltrifluoroborates have been accomplished in high yields using commercially-available [Rh(cod)(OH)]2 catalyst. The selective formation of the 2,6-trans-tetrahydropyran stereoisomer is consistent with a mechanism involving alkene association and carbometalation on the less hindered face of the dihydropyranone.
authors: Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK. han.j.edwards@gmail.com.
authors: Hannah J
authors: HJ
authors: Edwards
authors: Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK. sg297@bath.ac.uk.
authors: Sean
authors: S
authors: Goggins
authors: Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK. c.g.frost@bath.ac.uk.
authors: Christopher G
authors: CG
authors: Frost
mesh_terms: D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D061565:Cycloaddition Reaction; D012238:Rhodium / Q000737:chemistry*
chemical_list: D001897:Boronic Acids; D012238:Rhodium