Preparation of a chiral ferrocenyl derivative containing a biphenyl unit via nickel-mediated homocoupling.
Ferrocenyl derivative 2, which possesses a biphenyl unit, was prepared by nickel(0)-mediated homocoupling of a chiral ferrocenyloxazoline. Compound 2 exists as an equilibrium mixture of two diastereomers, in a ratio dependent on temperature and solvent, due to the partially hindered rotation around biaryl bond. Upon complexation with Cu(I) or Zn(II), complete fixation of the stereogenic axis was obtained and a single stable atropoisomer was formed, whose absolute configuration was assigned on the basis of its NOESY spectrum. The 2-Cu(I) complex was used as catalyst in the cyclopropanation of styrene.
Patti
Angela
A
Istituto di Chimica Biomolecolare del CNR, Sezione di Catania, Via del Santuario 110, I-95028 Valverde CT, Italy. angela.patti@icb.cnr.it
Pedotti
Sonia
S
D001713:Biphenyl Compounds / Q000737:chemistry*; D003521:Cyclopropanes / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D013237:Stereoisomerism; D020058:Styrene / Q000737:chemistry
D001713:Biphenyl Compounds; D003521:Cyclopropanes; D005296:Ferrous Compounds; D008024:Ligands; D009532:Nickel; D020058:Styrene; C010574:biphenyl; C030797:cyclopropane