Dimethylaminoalkyl chalcogenolate palladium(II) complexes as an efficient copper- and phosphine-free catalyst for Sonogashira reaction

- Sonogashira coupling using [PdCl(E∩NMe2)]n complexes catalyst.
- Dimeric and trimeric Pd(II) complexes of hemi-labile chalcogenolate ligands.
- Sonogashira cross-coupling reaction in the absence of copper and phosphine ligand.
- Dimeric complexes show better activity than mono and trimeric complexes.
- Selenium containing dimeric complex shows better activity than sulfur counterpart.

N,N-Dimethylaminoalkyl chalcogenolate Pd(II) complexes [PdCl(E∩NMe2)]n has been investigated as a moisture/air-stable and robust catalyst for Sonogashira cross-coupling reaction in the absence of copper and phosphine ligand. The dimeric palladium(II) complex of selenium containing ligand shows the best catalytic activity as compared with monomeric and trimeric complexes. The variety of functional groups are tolerated under optimized catalytic systems and provide excellent yields of the products.