title: Synthesis of Ruthenium Boryl Analogues of the Shvo Metal-Ligand Bifunctional Catalyst.
abstract: Metal boryl complexes have received significant attention in the literature in recent years due to their role as key intermediates in a number of metal-catalyzed borylation reactions. The ligand scaffold is known to have a significant impact on the observed reactivity of these metal boryl complexes. A synthetic strategy to access ruthenium boryl analogues of the Shvo metal-ligand catalysts is described. Heating a precursor to Shvo's catalyst (1) with bis(catecholato)diboron at 50 °C provided ruthenium boryl complex 3 [2,5-Ph(2)-3,4-Tol(2)(η(5)-C(4)COBcat)Ru(CO)(2)Bcat] (Bcat = catecholatoboryl). Addition of bis(catecholato)diboron to complex 1 in the presence of a phenol results in ruthenium boryl complex5 [2,5-Ph(2)-3,4-Tol(2)(η(5)-C(4)COH)Ru(CO)(2)Bcat] at 22 °C in 30% isolated yield. A single crystal X-ray analysis of complex 5 confirmed the assigned structure. An improved synthesis of ruthenium boryl complex 5 was developed by the in situ formation of complex 3 [2,5-Ph(2)-3,4-Tol(2)(η(5)-C(4)COBcat)Ru(CO)(2)Bcat] followed by addition of the phenol, resulting in a 51% yield.
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, Washington 98225-9150.
authors.forename: Liza
authors.initials: L
authors.lastname: Koren-Selfridge
authors.forename: Ian P
authors.initials: IP
authors.lastname: Query
authors.forename: Joel A
authors.initials: JA
authors.lastname: Hanson
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Isley
authors.forename: Ilia A
authors.initials: IA
authors.lastname: Guzei
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Clark