A new class of 3 '-sulfonyl BINAPHOS ligands: Modulation of activity and selectivity in asymmetric palladium-catalysed hydrophosphorylation of styrene

Katalin Barta, Giancarlo Francio, Walter Leitner, Guy C. Lloyd-Jones*, Ian R. Shepperson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Palladium-catalysed monophosphorylation of (R)-2,2'-bisperfluoroalkanesulfonates of BINOL (R(F) =CF(3) or C(4)F(9)) by a diaryl phosphinate [Ar(2)P(O)H] followed by phosphine oxide reduction (Cl(3)SiH) then lithium diisopropylamide-mediated anionic thia-Fries rearrangement furnishes enantiomerically-pure (R)-2'-diarylphosphino-2'-hydroxy-3'perfluoralkanesulfonyl-1,1'-binaphthalenes [(R)-8ab and (R)-8g-j], which can be further diversified by Grignard reagent (RMgX)-mediated CF(3)-displacement [->(R)-8c-f]. Coupling of (R)-8a-j with (S)1,1'-binaphthalene-2,2'-dioxychlorophosphine (S)-9 generates 3'-sulfonyl BINAPHOS ligands (R,S)-10a-j in good yields (43-82%). These new ligands are of utlility in the asymmetric hydrophosphonylation of styrene (1) by 4,4,5,5-tetramethyl-1,3,2-dioxaphospholane 2-oxide (2), for which a combination of the chiral ligands with either [Pd(Cp)(allyl)] or [Pd(allyl)(MeCN)(2)](+)/NaCH(CO(2)Me)(2) proves to be a convenient and active pre-catalyst system. A combination of an electron-rich phosphine moiety and an electron-deficient 3'-sulfone moiety provides the best enantioselectivity to date for this process, affording the branched 2-phenethenephosphonate, (-)-iso-3, in up to 74% ee with ligand (R,S)-10i, where Ar=p-anisyl and the 3'-SO(2)R group is triflone.

Original languageEnglish
Pages (from-to)2013-2023
Number of pages11
JournalAdvanced Synthesis & Catalysis
Volume350
Issue number13
DOIs
Publication statusPublished - Sep 2008

Keywords

  • asymmetric catalysis
  • BINOL
  • hydrophosphination
  • palladium
  • phosphines
  • phosphites
  • THIA-FRIES REARRANGEMENT
  • ENANTIOSELECTIVE SYNTHESIS
  • RHODIUM(I) COMPLEXES
  • PHOSPHINE-PHOSPHITE
  • ACTIVATED OLEFINS
  • ORGANIC-SYNTHESIS
  • METAL-COMPLEXES
  • EFFICIENT
  • HYDROFORMYLATION
  • HYDROGENATION

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