title: A sequential Pd/norbornene-catalyzed process generates o-biaryl carbaldehydes or ketones via a redox reaction or 6H-dibenzopyrans by C-O ring closure.
abstract: o-Biaryl carbaldeydes and ketones are obtained through the one-pot reaction of o-aryl iodides with o-bromobenzyl alcohols under the catalytic action of Pd and norbornene, in the presence of a base. The same reaction can also give dibenzopyrans by Pd and norbornene catalysis with a different termination, leading to C-O ring closure. In both cases the process first leads to a five-membered palladacycle, which controls C-C coupling, then to a seven-membered oxapalladacycle, which gives aldehydes and ketones or dibenzopyrans.
authors.affiliation: Dipartimento di Chimica and CIRCC, Università di Parma, Parco Area delle Scienze, 17/A, 43124 Parma, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Motti
authors.forename: Nicola
authors.initials: N
authors.lastname: Della Ca'
authors.forename: Di
authors.initials: D
authors.lastname: Xu
authors.forename: Anna
authors.initials: A
authors.lastname: Piersimoni
authors.forename: Elena
authors.initials: E
authors.lastname: Bedogni
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Zhou
authors.forename: Marta
authors.initials: M
authors.lastname: Catellani
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D001578:Benzopyrans / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D006842:Hydrocarbons, Brominated / Q000737:chemistry; D006847:Hydrocarbons, Iodinated / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*
chemical_list: D000438:Alcohols; D000447:Aldehydes; D001578:Benzopyrans; D006842:Hydrocarbons, Brominated; D006847:Hydrocarbons, Iodinated; D007659:Ketones; D010165:Palladium