Copper(I)-Catalyzed Synthesis of Unsymmetrical All-Carbon Bis-Quaternary Centers at the Opposing α-Carbons of Cyclohexanones

Org Lett. 2022 Jul 8;24(26):4810-4815. doi: 10.1021/acs.orglett.2c01890. Epub 2022 Jun 29.

Abstract

We describe a new synthetic reaction that generates all-carbon bis-quaternary centers at the opposing side of α-carbons in cyclohexanone with four different substituents in a controlled manner. Catalyzed by Cu(MeCN)4BF4 salt, this chemistry is proposed to proceed via an intermediacy of unsymmetrical O-allyl oxyallyl cations, which undergo a sequence of regioselective nucleophilic addition with substituted indoles and diastereoselective Claisen rearrangement in a single synthetic operation. The stereochemical outcome of the products features the cis diastereorelationship between the two aryl groups at the α,α'-positions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Carbon
  • Catalysis
  • Copper*
  • Cyclohexanones*
  • Stereoisomerism

Substances

  • Cyclohexanones
  • Carbon
  • Copper