Two Green Protocols for Halogenative Semipinacol Rearrangement

J Org Chem. 2023 Jan 6;88(1):504-512. doi: 10.1021/acs.joc.2c02496. Epub 2022 Dec 8.

Abstract

Semipinacol rearrangement is a special type of Wagner-Meerwein rearrangement that involves carbocation 1,2-rearrangement to provide carbonyl compounds with an α-quaternary carbon center. It has been strategically used for natural product synthesis and construction of highly congested quaternary carbons. Herein, we report a safe and green protocol that uses oxone/halide and Fenton bromide to achieve halogenative semipinacol rearrangement. The key feature of this method is the green in situ generation of reactive halogenating species from oxidation of halide with oxone or H2O2, which produces a nontoxic byproduct (potassium sulfate or water). Easy operation (insensitive to air and moisture) at room temperature without using special equipment adds additional advantage over previous methods.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclization
  • Cyclohexenes*
  • Hydrogen Peroxide*

Substances

  • potassium peroxymonosulfuric acid
  • semipinacol
  • Hydrogen Peroxide
  • Cyclohexenes