Synthesis of fluorous sulfur/carbon/sulfur pincer ligands and palladium complexes: New catalyst precursors for the Heck reaction

Rosenildo Da Costa, Markus Jurisch, John A. Gladysz

Research output: Contribution to journalArticlepeer-review

Abstract

Reactions of 1,3-C6H4(CH2Br)2 and the thiols HSCH2CH2Rfn (Rfn=(CF2)n−1CF3; n=8, 10), or the dithiol 1,3-C6H4(CH2SH)2 and ICH2CH2Rfn, in the presence of carbonate or NaOEt (70–78°C) give the title ligands 1,3-C6H4(CH2SCH2CH2Rfn)2 (4-Rf8, 58–61%; 4-Rf10, 49–50%). Reactions of 4-Rfn and Pd(OC(O)CF3)2 or (PhCN)2Pd(Cl)2 (80°C) afford the title complexes (n/X=8/OC(O)CF3 (5-Rf8), 44%; 10/OC(O)CF3, 58%; 8/Cl (6-Rf8), 45%; 10/Cl, 79%). Both 5-Rf8 and 6-Rf8 are effective catalyst precursors for the Heck reaction of iodobenzene and methyl acrylate (0.21–0.23mol%, DMF, i-Pr2NEt, 100–125°C). However, no active catalyst can be recycled by a subsequent extraction with fluorous solvents. Rather, activity remains in the reddish DMF phase, and is quenched by the addition of mercury. Palladium nanoparticles are visible by transmission electron microscopy. These, or low valent species derived therefrom, are believed to be the active catalysts, in accord with other recent studies involving related non-fluorous and fluorous palladacycles. The CF3C6F11/toluene partition coefficients of representative compounds are determined.

Original languageEnglish
Pages (from-to)3205-3214
JournalInorganica Chimica Acta
Volume361
Issue number11
DOIs
Publication statusPublished - 2008

Fingerprint

Dive into the research topics of 'Synthesis of fluorous sulfur/carbon/sulfur pincer ligands and palladium complexes: New catalyst precursors for the Heck reaction'. Together they form a unique fingerprint.

Cite this