Chemo- and Regioselective Multiple C(sp2 )-H Insertions of Malonate Metal Carbenes for Late-Stage Functionalizations of Azahelicenes

Angew Chem Int Ed Engl. 2022 Oct 10;61(41):e202210798. doi: 10.1002/anie.202210798. Epub 2022 Sep 1.

Abstract

Chiral quinacridines react up to four times, step-by-step, with α-diazomalonates under RuII and RhII catalysis. By selecting the catalyst, [CpRu(CH3 CN)3 ][PF6 ] (Cp=cyclopentadienyl) or Rh2 (oct)4 , chemo and regioselective insertions of derived metal carbenes are achieved in favor of mono- or bis-functionalized malonate derivatives, respectively, (r.r.>49 : 1, up to 77 % yield, 12 examples). This multi-introduction of malonate groups is particularly useful to tune optical and chemical properties such as absorption, emission or Brønsted acidity but also cellular bioimaging. Density-functional theory further elucidates the origin of the carbene insertion selectivity and also showcases the importance of conformations in the optical response.

Keywords: Carbenes; C−H Insertion; Helicenes; Late-Stage Functionalization; Photophysical Properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Malonates
  • Methane* / analogs & derivatives
  • Methane* / chemistry
  • Molecular Structure
  • Rhodium* / chemistry

Substances

  • Malonates
  • carbene
  • Rhodium
  • Methane