Improved synthesis of pincer ligand precursor, and synthesis and structural characterization of terphenyl scaffolded S–C–S palladium pincer complex

An easier and more expedient synthesis of 2,6-(BrCH2C6H4)2-4-I-C6H3 (2) is reported. This material allowed easy synthesis of the new pincer ligand precursor 2,6-(4-CH3C6H4SCH2C6H4)2-4-I-C6H3 (3) in 87% yield. Compound 3 reacts with Pd2(dba)3 to give the new palladium pincer complex 4. Compound 4 has been fully characterized, including structural characterization by single crystal X-ray diffraction methods. The results of the crystallographic work on 4 reveal a twisted type pincer complex not unlike related terphenyl pincer complexes.

Graphical abstractA quicker preparation of terphenyl pincer ligand intermediate has been developed, and used to prepare a new S–C–S pincer ligand precursor. The new S–C–S palladium pincer complex has been prepared from this ligand precursor and structurally characterized.Figure optionsDownload full-size imageDownload as PowerPoint slide