cis-Dichloro Sulfoxide Ligated Ruthenium Metathesis Precatalysts

Abstract

Novel sulfoxide-ligated ruthenium complexes were prepared by reacting second-generation metathesis precatalysts with p-toluenesulfonyl chloride in the presence of a small excess of sulfoxide. (SIMes)Ru(S-DMSO)(Ind)Cl 2 (M54) and (SIMes)Ru(S-DMSO)(CHPh)Cl 2 (M54a) were characterized crystallographically and, in agreement with NMR spectroscopy, were found to adopt an unusual cis-dichloro configuration. Despite having traditionally latent geometry, the new complexes were found to be highly reactive precatalysts for routine metathesis transformations. Additionally, the robustness, scalability, and industrial utility of M54 as a ruthenium synthon are demonstrated.

Light‐Driven gem Hydrogenation: An Orthogonal Entry into “Second‐Generation” Ruthenium Carbene Catalysts for Olefin Metathesis

“…This handicap could be avoided by turning the ruthenacyclic ring by 90 °C such that it lies parallel rather than orthogonal to the mesityl group; such an arrangement requires the chloride ligands to be cis ‐oriented. Although less widespread, ruthenium carbene complexes with such an overall coordination geometry are well known; they are commonly observed upon formal replacement of the ether oxygen of an archetype Grubbs‐Hoveyda catalyst by heteroatoms exerting a stronger trans influence [18–23] . Provided that alkynes carrying appropriate such substituents are amenable to the light‐driven gem hydrogenation, the resulting ruthenium carbene complexes could adopt the desirable coordination geometry, which in turn might potentially improve the outcome of the reaction in terms of selectivity, efficiency and yield.…”

Imposing Latency in Ruthenium Sulfoxide-Chelated Benzylidenes: Expanding Opportunities for Thermal and Photoactivation in Olefin Metathesis

“…The novel ruthenium complex was fully characterized by 1 Hand 13 C NMR, HR-MS, UV−vis, and single crystal X-ray spectroscopy (Figure 2). Several insights regarding the structure of 8 could be attained from its synthesis and characterization.…”

“…Table compares critical bond lengths between complex 8 and relevant examples of both cis -dichloro and trans -dichloro S-chelated complexes from the literature. ,, Notably, the Ru–S bond in complex 8 is significantly shorter than the Ru–S bond in cis -dichloro thioether complex 10 (2.258 Å vs 2.347 Å) (and also shorter than the Ru–S bond for a recently reported nonchelated DMSO complex), making this the shortest Ru–S bond to date for S-chelated Ru alkylidenes. In addition, 8 also portrays the shortest C benzylidene –Ru bond for all the complexes shown.…”

“…Synthetic procedures and characterization ( 1 H-, 13 C NMR, and HRMS), crystallographic data summary for 8, DFT computational details, NMR spectra of thermal and photoactivated metathesis and GC-MS analyses (PDF) (CIF) (TXT1, TXT2, TXT3, TXT4, TXT5, TXT6)…”

Amino complexo de Ru-dmso como pré-catalisador para reação de polimerização: estudo cinético e mecanístico

“…Alguns outros objetivos com relevância industrial incluem altos rendimentos, facilidade de síntese e purificiação, insumos tornar os protocolos de síntese mais viáveis para área acadêmica e(MÜLLER et al, 2019;NUBEL;HUNT, 1999) Uma das alternativas promissoras está na química de coordenação dos compostos com sulfóxidos, originada na década de 60 com atividade potencial em (SILVA; TOMA, 1993) Um dos precursores de síntese é o dmso) 3 ] devido à sua versatilidade associada com a natureza /Odmso coordenado (CALLIGARIS, 1996). Pré-catalisadores de rutênio ligados a sulfóxido quando aplicados em metátese são contribuição catalisadores atualmente disponíveis (JOHNS et al, 2019). Sulfóxidos como ligantes em catalisadores para metátese O dimetilsulfóxido (dmso) é um ligante ambidentado e pode se ligar ao centro metálico através do átomo de oxigênio (O-dmso) ou do enxofre S de uma molécula de dmso pode ser considerada como existindo em três for canônicas, como ilustrado na Figura 6 (CALLIGARIS, 2004).…”