Pd(ii) complexes with amide-based macrocycles: syntheses, properties and applications in cross-coupling reactionsElectronic supplementary information (ESI) available: Figures for the absorption and NMR spectra and crystal structures and tables for NMR data, weak interactions, electrochemical data, and data collection and structure solution parameters. CCDC 848812-848815. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4nj01300j

• Main Authors: Kumar, Sushil, Jha, Rajeev Ranjan, Yadav, Sunil, Gupta, Rajeev
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c4nj01300j

This work shows Pd( ii ) complexes in a set of 13-membered amide-based macrocyclic ligands varied by the placement of e − -donating and e − -withdrawing substituents on the ligand framework. Ligands constitute a N 4 square-planar cavity and optimally house the Pd( ii ) ion. The solution-state structure via NMR and absorption spectra substantiates the solid-state structure obtained by crystallography. The electrochemical studies display the impact of electronic substituents on ligands that significantly influence the redox properties and also shift the locus of oxidation. These complexes were used in the Suzuki and Heck cross-coupling reactions. The moderate cross-coupling reaction results are due to limited redox accessibility that can be improved either by using substrates with a better leaving group or by placing electron-withdrawing substituents on the macrocyclic ligands. Square-planar Pd 2+ complexes of macrocyclic ligands carrying electronic substituents are synthesized and characterized. These well-characterized complexes have been used in the Suzuki and Heck cross-coupling reactions.