Brønsted Acid versus Phase-Transfer Catalysis in the Enantioselective Transannular Aminohalogenation of Enesultams

Chemistry. 2022 Nov 7;28(62):e202202267. doi: 10.1002/chem.202202267. Epub 2022 Oct 17.

Abstract

We have studied the enantioselective transannular aminohalogenation reaction of unsaturated medium-sized cyclic benzosulfonamides by using both chiral Brønsted acid and phase-transfer catalysis. Under optimized conditions, a variety of bicyclic adducts can be obtained with good yields and high enantioselectivities. The mechanism of the reaction was also studied by using computational tools; we observed that the reaction involves the participation of a conformer of the nine-membered cyclic substrate with planar chirality in which the stereochemical outcome is controlled by the relative reactivity of the two pseudorotational enantiomers when interacting with the chiral catalyst.

Keywords: ELF; asymmetric catalysis; computational chemistry; electrophilic addition; medium-ring compounds; transannular reactions.

MeSH terms

  • Acids*
  • Catalysis
  • Stereoisomerism

Substances

  • Acids