Thioether-functionalized ferrocenyl-bis(phosphonite), Fe{(C5H4)P(-OC10H6(micro-S)C10H6O-)}2: synthesis, coordination behavior, and application in Suzuki-Miyaura cross-coupling reactions.
The thioether-functionalized metalloligand ferrocenyl-bis(phosphonite), Fe(C5H4PR)2 (4, R=-OC10H6(micro-S)C10H6O-) is synthesized in three steps starting from ferrocene, and its coordination behavior toward various transition-metal derivatives is described. The reactions of 4 with [Rh(CO)2Cl]2 or M(COD)Cl2 afforded the chelate complexes, cis-[Rh(CO)Cl{Fe(C5H4PR)2-kappaP,kappaP}] (5) or cis-[MCl2{Fe(C5H4PR)2-kappaP,kappaP}] (6, M=PdII; 7, M=PtII), respectively. However, treatment of 4 with CuX (X=Cl, Br, and I) produces binuclear complexes, [Cu2(micro-X)2(MeCN){Fe(C5H4PR)2-kappaP,kappaP}] (8, X=Cl; 9, X=Br; 10, X=I) where the sulfur atom on one side of the ligand is involved in a weak interaction with the copper center. Reaction of 4 with 1 equiv of Ag(PPh3)OTf gives the mononuclear chelate complex [Ag(OTf)PPh3{Fe(C5H4PR)2-kappaP,kappaP}] (11), whereas treatment with 2 equiv of AuCl(SMe2) produces the dinuclear gold complex [Au(Cl){Fe(C5H4PR)2-kappaP,kappaP}Au(Cl)] (12). The crystal structures of 10 and 12 are reported, where a strong metallophilic interaction is observed between the closed-shell metal centers. The palladium complex 6 catalyzes the Suzuki cross-coupling reactions of aryl bromides with phenylboronic acid with excellent turnover numbers (TON up to 1.36x10(5)).
Punji
Benudhar
B
Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
Mague
Joel T
JT
Balakrishna
Maravanji S
MS
D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D000075163:Metallocenes; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry; D013440:Sulfides / Q000138:chemical synthesis* / Q000737:chemistry
D005296:Ferrous Compounds; D000075163:Metallocenes; D009942:Organometallic Compounds; D013440:Sulfides; D010165:Palladium; D003300:Copper; D012238:Rhodium; C004998:ferrocene