title: Competitive Ring Expansion of Azetidines into Pyrrolidines and/or Azepanes.
abstract: Azetidines fitted with a 3-hydroxypropyl side chain at the 2-position undergo intramolecular N-alkylation after activation of the primary alcohol, and the produced 1-azonia-bicyclo[3.2.0]heptane is opened by different nucleophiles (cyanide, azide, or acetate anions) to produce mixtures of ring expanded pyrrolidines and azepanes, or a unique type of compound. Distribution of produced five- or seven-membered rings depends on the substitution pattern on the azetidine ring and on its side chain, together with the nature of the nucleophile used in the expansion process. Observed regioselectivities for nucleophilic opening are rationalized by quantum mechanical DFT calculations and are in good agreement with experimental results.
authors.affiliation: Institut Lavoisier de Versailles, UMR 8180, Université de Versailles St-Quentin-en-Yvelines, Université Paris Saclay - 45 , av. des Etats-Unis, 78035 Versailles Cedex, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Drouillat
authors.affiliation: Institute of Physical and Organic Chemistry, Southern Federal University , 194/2 Stachka Ave., 344090 Rostov-on-Don, Russian Federation.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Dorogan
authors.affiliation: Department of Chemistry, Southern Federal University , 7, Zorge St., 344090, Rostov-on-Don, Russian Federation.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Kletskii
authors.affiliation: Department of Chemistry, Southern Federal University , 7, Zorge St., 344090, Rostov-on-Don, Russian Federation.
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Burov
authors.affiliation: Institut Lavoisier de Versailles, UMR 8180, Université de Versailles St-Quentin-en-Yvelines, Université Paris Saclay - 45 , av. des Etats-Unis, 78035 Versailles Cedex, France.
authors.forename: François
authors.initials: F
authors.lastname: Couty