Accessing Illusive E Isomers of α-Ester Hydrazones via Visible-Light-Induced Pd-Catalyzed Heck-Type Alkylation

Org Lett. 2022 Jun 17;24(23):4176-4181. doi: 10.1021/acs.orglett.2c01409. Epub 2022 Jun 2.

Abstract

A visible-light-induced Pd-catalyzed stereoselective synthesis of alkylated ester hydrazones has been developed. This method operates via generation of a nucleophilic carbon-centered radical from alkyl bromide, iodide, or redox-active ester, followed by its addition to hydrazone, and a subsequent desaturation by palladium. The majority of products have E configuration, which are inaccessible by conventional condensation methods. In addition, a sequential C,N-alkylation protocol has been developed: a reaction between 1,3-dihalides and glyoxylate-derived hydrazone, delivering tetrahydropyridazines.

Publication types

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

MeSH terms

  • Alkylation
  • Catalysis
  • Esters
  • Hydrazones*
  • Palladium*

Substances

  • Esters
  • Hydrazones
  • Palladium