title: Tandem Aryne-Capture/Sigmatropic Rearrangement as a Metal-Free Entry to Functionalized N-Aryl Pyrrolidines.
abstract: We report a new method for the synthesis of novel N-aryl proline analogues. By reacting an aryne precursor with N-(2-malonyl) tetrahydropyridines in the presence of tetrabutylammonium fluoride (TBAF), a tandem aryne-capture/anion isomerisation/[2,3]-sigmatropic rearrangement is induced, leading to good yields of 3-substituted N-aryl-2-acylpyrrolidines. These products are known subunits of biological probes, sensors and drug-like fragments, and are not easily accessed directly by other methods. The reaction is also notable as the first [2,3]-rearrangement of cyclic ammonium ylides at room temperature.
authors.affiliation: Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors.forename: Sam G
authors.initials: SG
authors.lastname: Moss
authors.affiliation: Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Pocock
authors.affiliation: Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK.
authors.forename: Joseph B
authors.identifier: http://orcid.org/0000-0001-7593-9598
authors.initials: JB
authors.lastname: Sweeney
keywords: N-aryl pyrrolidine; metal-free; sigmatropic rearrangement; tandem; ylides