title: Hybrids of sugars and aromatics: A Pd-catalyzed modular approach to chromans and isochromans.
abstract: Herein we describe the synthesis of highly substituted chromans and isochromans using carbohydrates as starting materials. The key step of our synthetic approach is the annelation of the benzene moiety via a highly efficient Pd-catalyzed domino reaction. This powerful approach led to a small library of highly substituted chromans and isochromans by making use of a variety of different diynes and bromoglycals. We investigated several Pd-catalysts in order to improve the yields and to enlarge the scope of the domino reaction. Furthermore, we elucidated the mechanistic picture of the reaction with isotope-labelling experiments. Most probably the reaction proceeds via an oxidative addition followed by two carbopalladation steps and a final cyclization reaction.
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077 Göttingen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Leibeling
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Koester
authors.forename: Martin
authors.initials: M
authors.lastname: Pawliczek
authors.forename: Daniel
authors.initials: D
authors.lastname: Kratzert
authors.forename: Birger
authors.initials: B
authors.lastname: Dittrich
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Werz
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D002839:Chromans / Q000138:chemical synthesis*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D007553:Isotope Labeling; D010165:Palladium; D054852:Small Molecule Libraries / Q000138:chemical synthesis
chemical_list: D002241:Carbohydrates; D002839:Chromans; D006841:Hydrocarbons, Aromatic; D054852:Small Molecule Libraries; D010165:Palladium