Ruthenium Catalysts for the Kharasch Reaction

Abstract

Recent advances in the development of ruthenium catalysts for the atom transfer radical addition of polyhalogenated compounds to olefins ('Kharasch reaction') are described. Three classes of homogeneous catalysts are discussed: halfsandwich complexes with η 6 -arene, η 5 -cyclopentadienyl or η 5 -carborane ligands, ruthenium complexes with alkylidene-or vinylidene ligands and polynuclear complexes. Furthermore, first attempts to use immobilized ruthenium complexes as heterogeneous catalysts for the Kharasch reaction are summarized.

Highly Efficient Ambient‐Temperature Copper‐Catalyzed Atom‐Transfer Radical Addition (ATRA) in the Presence of Free‐Radical Initiator (V‐70) as a Reducing Agent

“…[2] Today, this reaction is known as the Kharasch addition or atomtransfer radical addition (ATRA), and it is typically catalyzed by transition-metal complexes of Ru, Fe, Ni, and Cu. [3][4][5][6] Transition-metal-catalyzed ATRA, despite being discovered nearly 40 years before the widely used tin-mediated radical addition to olefins [7] and iodine atom-transfer radical addition, [8] is still not fully utilized as a technique in organic synthesis. Until recently, the principal reason for small participation of ATRA in complex molecule and natural product syntheses remained the large amount of transition metal needed to achieve high selectivity towards the desired target compound (typically 5-30 mol % relative to alkene).…”

Catalytic Synthesis and Antifungal Activity of New Polychlorinated Natural Terpenes

“…On the other hand, it is a synthetically useful process for functionalizing organic compounds by means of halogen derivatives with a high level of atom economy. Kharasch addition is typically catalyzed by transition metal complexes of Cu, Ru, Fe, or Ni [10,[12][13][14]. However, although the Kharasch addition of CCl 4 to simple alkenes has been extensively studied [12][13][14], to our knowledge no works have been devoted to the corresponding reactions using natural terpenic alkenes.…”

Immobilized copper catalyst for atom transfer radical addition and polymerization

“…[1,2] A wide range of metal catalysts have been reported in ATRA, such as copper, [3,4] nickel, [5] iron [6,7] and ruthenium [8 -10] complexes. Verpoort et al [11] reported an immobilized multifunctional Schiff bases containing ruthenium complexes on MCM-41 and used them for ATRA.…”