Roffe, Gavin, Boonseng, Sarote, Baltus, Christine, Coles, Simon, Day, Iain, Jones, Rhiannon, Press, Neil, Ruiz, Mario, Tizzard, Graham, Cox, Hazel and Spencer, John (2016) A Synthetic, Catalytic and Theoretical Investigation of an Unsymmetrical SCN Pincer Palladacycle. Royal Society Open Science, 3 (4). p. 150656. ISSN 2054-5703

Abstract

The SCN ligand, 2-{3-[(methylsulfanyl)methyl]phenyl}pyridine, 1 has been synthesized starting from an initial Suzuki-Miyaura coupling between 3-((hydroxymethyl)phenyl)boronic acid and 2-
bromopyridine. The C-H activation of 1 with in situ formed Pd(MeCN)4(BF4)2 has been studied and
leads to a mixture of palladacycles, which were characterized by X-ray crystallography. The
monomeric palladacycle LPdCl 6, where L-H = 1, has been synthesized, and tested in Suzuki-Miyaura couplings of aryl bromides, where it showed moderate activity. DFT and the Atoms in Molecules (AIM) method have been used to investigate the formation and bonding of 6, revealing a difference in the nature of the Pd-S and Pd-N bonds. It was found that S-coordination to the metal in the rate determining C-H bond activation step leads to better stabilization of the Pd(II) centre (by 13 – 28 kJ mol-1) than with N-coordination. This is attributed to the electron donating ability of the donor atoms determined by Bader charges. The AIM analysis also revealed that the Pd-N bonds are stronger than the Pd-S bonds influencing the stability of key intermediates in the palladacycle
formation reaction pathway.

Item Type:	Article
Date Deposited:	20 May 2016 23:45
Last Modified:	20 May 2016 23:45
URI:	https://oak.novartis.com/id/eprint/28698