Base-promoted elimination reactions of (E)- and (Z)-arylaldehyde O-benzoyloximes. Effects of stereochemistry, β-aryl group, and base-solvent on the nitrile-forming transition states

Sang Yong Pyuna, Bong-Rae Cho

Research output: Contribution to journalArticle

Abstract

This account summarizes the results of mechanism studies on the nitrile-forming eliminations from (E)- and (Z)-arylaldehyde O-benzoyloximes promoted by 1,8-diazabicyclo-[5.4.0]undec-7- ene (DBU) in MeCN, R1R2NH in MeCN, and R1R2NH/R1R2NH2 + in 70mol% MeCN(aq). The rate of anti-elimination was 36,000-fold faster than that of syn-elimination. The change of the β- aryl group from Ph to thienyl to furyl shifted the E2 transition state slightly towards product-like. When (E)-2,4-dinitrobenzaldehyde O-benzoyloxime was employed as the reactant and R1R2NH/R1R2NH2 + in 70mol% MeCN(aq) was used as the base-solvent, the (E1cb)irr was observed.

Original languageEnglish
Pages (from-to)118-137
Number of pages20
JournalArkivoc
Volume2010
Issue number7
Publication statusPublished - 2010 Jul 15

    Fingerprint

Keywords

  • E1cb mechanism
  • E2 mechanism
  • Elimination
  • Transition state

ASJC Scopus subject areas

  • Organic Chemistry

Cite this