Hydrovinylation of Alkenes Catalyzed by the Ruthenium−Hydride Complex Formed in Situ from (PCy₃)₂(CO)RuHCl and HBF₄·OEt₂

Abstract

A ruthenium-hydride complex, generated in situ from the reaction of (PCy 3 ) 2 (CO)RuHCl ( 1) with HBF 4 ‚OEt 2 , was found to be an effective catalyst for the hydrovinylation of alkenes. For example, the reaction of styrene with ethylene in the presence of 1/HBF 4 ‚OEt 2 (0.5 mol %) at room temperature produced the hydrovinylation product in 93% isolated yield. Both terminal alkenes and dienes were found to give the hydrovinylation products. Higher reaction temperature was required for the phenyl-substituted internal alkenes, in which cases the isomerized products were obtained.

Catalysis at the Interface of Ruthenium Carbene and Ruthenium Hydride Chemistry: Organometallic Aspects and Applications to Organic Synthesis

“…[52,53] The hydride 38, for instance, which had previously been prepared [54] from RuCl 3 , PCy 3 , and methanol, [55] is an efficient catalyst for hydrogenation, [48,50,56,57] isomerization, [47,48] and hydrovinylation. [58] Similar catalytic activity has been described for hydride complexes bearing a saturated [48] or an unsaturated [50] N-heterocyclic carbene ligand.…”

“…[86] It has been noted previously that the efficiency of 38 can be enhanced significantly by the addition of HBF 4 . [58] The catalytic system 38/HBF 4 has, for instance, been used to promote the transformation 94 Ǟ 95 outlined in Scheme 26. …”

Regioselective Hydrohydroxyalkylation of Styrene with Primary Alcohols or Aldehydes via Ruthenium‐Catalyzed C−C Bond Forming Transfer Hydrogenation

“…We were inspired by Yi’s observation [10] that the addition of HBF 4 •OEt 2 to the ruthenium-hydride complex HClRu(CO)(PCy 3 ) 2 dramatically enhances catalytic activity in alkene hydrogenation [10a] and hydrovinylation. [10b] As corroborated by Yi’s mechanistic studies, HBF 4 opens a coordination site at ruthenium by protonating a tricyclohexylphosphine ligand.…”

“…We were inspired by Yi’s observation [10] that the addition of HBF 4 •OEt 2 to the ruthenium-hydride complex HClRu(CO)(PCy 3 ) 2 dramatically enhances catalytic activity in alkene hydrogenation [10a] and hydrovinylation. [10b] As corroborated by Yi’s mechanistic studies, HBF 4 opens a coordination site at ruthenium by protonating a tricyclohexylphosphine ligand. [10] In the hope that such coordinative unsaturation would unlock the transfer hydrogenative coupling of styrene with primary alcohols, [11,12] a series of experiments were conducted using the HClRu(CO)(PCy 3 ) 2 /HBF 4 •OEt 2 catalyst system (Scheme 1, eq.…”

Nickel‐Catalyzed Highly Selective Hydrovinylation of α‐Ketals of Vinylarenes

“…In 1965, Alderson and co-workers [3] reported a hydrovinylation of methyl acrylate catalyzed by rhodium or ruthenium at high temperature and obtained a mixture of hydrovinylation product and the dimer of methyl acrylate. In the ruthenium hydride complexcatalyzed hydrovinylation of a,b-unsaturated ketones and esters Yi et al [4] gained the hydrovinylation products with a double bond migration. Palladium [5] and nickel [6] catalysts with different ligands were also tested in the hydrovinylation of various functionalized olefins, however, low conversions or poor selectivities were generally obtained.…”