Tridentate Directing Groups Stabilize 6-Membered Palladacycles in Catalytic Alkene Hydrofunctionalization

J Am Chem Soc. 2017 Nov 8;139(44):15576-15579. doi: 10.1021/jacs.7b08383. Epub 2017 Oct 26.

Abstract

Removable tridentate directing groups inspired by pincer ligands have been designed to stabilize otherwise kinetically and thermodynamically disfavored 6-membered alkyl palladacycle intermediates. This family of directing groups enables regioselective remote hydrocarbofunctionalization of several synthetically useful alkene-containing substrate classes, including 4-pentenoic acids, allylic alcohols, homoallyl amines, and bis-homoallylamines, under Pd(II) catalysis. In conjunction with previous findings, we demonstrate regiodivergent hydrofunctionalization of 3-butenoic acid derivatives to afford either Markovnikov or anti-Markovnikov addition products depending on directing group choice. Preliminary mechanistic and computational data are presented to support the proposed catalytic cycle.

Publication types

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

MeSH terms

  • Alkenes / chemistry*
  • Amines / chemistry
  • Butyrates / chemistry
  • Catalysis
  • Fatty Acids, Monounsaturated / chemistry
  • Kinetics
  • Ligands
  • Palladium / chemistry*
  • Propanols / chemistry
  • Thermodynamics

Substances

  • Alkenes
  • Amines
  • Butyrates
  • Fatty Acids, Monounsaturated
  • Ligands
  • Propanols
  • allyl alcohol
  • Palladium
  • 3-butenoic acid
  • 4-pentenoic acid