title: Structurally Divergent Lithium Catalyzed Friedel-Crafts Reactions on Oxetan-3-ols: Synthesis of 3,3-Diaryloxetanes and 2,3-Dihydrobenzofurans.
abstract: The first examples of 3,3-diaryloxetanes are prepared in a lithium-catalyzed and substrate dependent divergent Friedel-Crafts reaction. para-Selective Friedel-Crafts reactions of phenols using oxetan-3-ols afford 3,3-diaryloxetanes by displacement of the hydroxy group. These constitute new isosteres for benzophenones and diarylmethanes. Conversely, ortho-selective Friedel-Crafts reactions of phenols afford 3-aryl-3-hydroxymethyl-dihydrobenzofurans by tandem alkylation-ring-opening reactions; the outcome of the reaction diverging to structurally distinct products dependent on the substrate regioselectivity. Further reactivity of the oxetane products is demonstrated, suitable for incorporation into drug discovery efforts.
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK.
authors.forename: Rosemary A
authors.initials: RA
authors.lastname: Croft
authors.affiliation: Pfizer Global Research and Development, 445 Eastern Point Rd., Groton, CT 06340, USA.
authors.forename: James J
authors.initials: JJ
authors.lastname: Mousseau
authors.affiliation: Pfizer Global Research and Development, 445 Eastern Point Rd., Groton, CT 06340, USA.
authors.forename: Chulho
authors.initials: C
authors.lastname: Choi
authors.affiliation: Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK. j.bull@imperial.ac.uk.
authors.forename: James A
authors.identifier: http://orcid.org/0000-0003-3993-5818
authors.initials: JA
authors.lastname: Bull
keywords: carbocations; homogeneous catalysis; lithium; oxetanes; oxygen heterocycles