Highly active ferrocenylamine-derived palladacycles for carbon–carbon cross-coupling reactions

{[(N-Methyl-N-p-R-benzyl)amino]benzyl}ferrocenes 4a–c (R = H(a), OCH3(b), CH3(c)) were synthesized by N-methylation of the corresponding sec-amines 3a–cwith the reagent CH3I-t-BuOK. Treatment of 4a–c with Na2PdCl4 in the presence of NaOAc produced a pair of palladacycles σ-Pd[(η5-C5H5)Fe(η5- C5H3CH(C6H5)N(CH3)CH2-C6H4-R)]Cl(PPh3) 5a–c (R = same as before) consisting of RNRP and SNSP configurations. The structure of 5a was determined by single crystal X-ray analysis. High catalytic activities of 5a–c for the Suzuki coupling of aryl chlorides with phenylboronic acid and the Heck reaction of bromobenzene with styrene were observed.

{[(N-Methyl-N-p-R-benzyl)amino]benzyl}ferrocenes4a–c were synthesized from sec-amines 3a–c and CH3I. Treatment of 4a–c with Na2PdCl4 produced a pair of palladacycles σ-Pd[(η5-C5H5)Fe(η5-C5H3CH(C6H5)N(CH3)CH2-C6H4-R)]Cl(PPh3) 5a–c, consisting of RNRP and SNSP configurations. High catalytic activities of 5a–c for the Suzuki coupling of aryl chlorides with phenylboronic acid and for the Heck reaction of bromobenzene with styrene were observed.Figure optionsDownload as PowerPoint slide