title: Thia-, aza-, and selena[3.3.1]bicyclononane dichlorides: rates vs internal nucleophile in anchimeric assistance.
abstract: Sulfur-, selenium-, and nitrogen-containing compounds bearing leaving groups in the β-position undergo facile substitution chemistry enabled by anchimeric assistance. Here we provide direct comparisons between such systems in the rigid bicyclo[3.3.1]nonane framework easily derived from 1,5-cyclooctadiene. For a series of dichloride electrophiles of this type, the relative reactivities were found to be Se ≫ (alkyl)N > S ≥ (propargyl)N > (phenyl)N, with the reaction rates at the two extremes differing by more than 3 orders of magnitude. For the N-alkyl case, substitution rates were largely independent of the trapping nucleophile but were strongly dependent on solvent, showing that the process is controlled by the formation of the high-energy three-membered cationic intermediate.
authors.affiliation: Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States.
authors.forename: Adrian A
authors.initials: AA
authors.lastname: Accurso
authors.forename: So-Hye
authors.initials: SH
authors.lastname: Cho
authors.forename: Asmarah
authors.initials: A
authors.lastname: Amin
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Potapov
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Amosova
authors.forename: M G
authors.initials: MG
authors.lastname: Finn
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D003516:Cycloparaffins / Q000737:chemistry*; D012643:Selenium / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*
chemical_list: D000473:Alkanes; D001372:Aza Compounds; D003516:Cycloparaffins; D013455:Sulfur; D012643:Selenium; C017573:nonane