title: Fluoride-free Hiyama coupling by palladium abnormal N-heterocyclic carbene complexes.
abstract: A series of palladium complexes of the abnormal N-heterocyclic carbene ligands of the type (a-NHC)PdI2(L) [L = NC5H5(1-3)b and PPh3(1-3)c] effectively catalyzed the Hiyama coupling of aryl bromides and iodides with PhSi(OMe)3 under the highly desired fluoride-free conditions. Interestingly enough, the pyridine based trans-(1-3)b complexes and a PPh3 derived cis-3c complex exhibited higher yields than the related PPh3 derived trans-(1-2)c complexes. The superior performances of the pyridine based trans-(1-3)b complexes and the PPh3 derived cis-3c complex have been correlated to a tighter binding of the a-NHC ligand to the palladium center in these complexes, leading to a greater (a-NHC) ligand influence on the metal center partaking in the catalysis.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India. pghosh@chem.iitb.ac.in.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Modak
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Gangwar
authors.forename: Mitta
authors.initials: M
authors.lastname: Nageswar Rao
authors.forename: Mahesh
authors.initials: M
authors.lastname: Madasu
authors.forename: Alok Ch
authors.initials: ACh
authors.lastname: Kalita
authors.forename: Vincent
authors.initials: V
authors.lastname: Dorcet
authors.forename: Mayuri Arun
authors.initials: MA
authors.lastname: Shejale
authors.forename: Ray J
authors.initials: RJ
authors.lastname: Butcher
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Ghosh