Open-Shell Organometallics as a Bridge between Werner-Type and Low-Valent Organometallic Complexes. The Effect of the Spin State on the Stability, Reactivity, and Structure.

Atmospheric oxygen was used for the first time as an oxidant in metal-catalyzed homocoupling of Grignard reagents. These manganese- or iron-catalyzed reactions are efficient, cheap, and eco-friendly. They are applicable to the large-scale synthesis of symmetrical conjugated compounds.

http://www.cs.gordon.edu/~ijl/che340/project/Manganese-%20or%20Iron-Catalyzed%20Homocoupling%20of%20Grignard%20Reagents%20Using%20Atmospheric%20Oxygen%20as%20an%20Oxidant.pdf

Manganese- or iron-catalyzed homocoupling of grignard reagents using atmospheric oxygen as an oxidant.

Carbon monoxide insertion into transition metal-carbon sigma-bonds

Reactive Organometallic Compounds Obtained from Metallocenes and Related Compounds and Their Synthetic Applications

Carbonyl-insertion reactions of square-planar complexes

Treatment of Mn(acac)3 (acac=acetylacetonato ligand) with AlPh3·Et2O in the presence of PCy3 (Cy=cyclo-C6H11) gave a new diphenylmanganese(II) complex, Ph2MnPCy3 (1). Complex 1 reacted with allylic compounds, CH2=CHCH2X (X=Br, OPh, OCH2CH=CH2, and OCOCH3), to give allylbenzene. Carbon dioxide was found to be inserted into the phenyl-manganese σ-bond of 1 to give bis(benzoato)manganese complex, (PhCOO)2MnPCy3, 2, which on successive treatment with HCl and diazomethane produced methyl benzoate. Complex 1 reacted with aldehydes, ketones, and esters having no active α-hydrogen atom to give alkoxomanganese species in solution, indicating that the insertion of C=O double bond into the phenyl-manganese σ-bond occurred. On the other hand, acetone and acetophenone reacted with Ph2MnPCy3 to give benzene and 2-oxoalkyl complexes, (RCOCH2)2Mn(PCy3)m (R=Me, Ph), 3. Reaction of alcohols with 1 afforded alkoxomanganese compounds which catalyze the Tishchenko type and Meerwein-Pondorf type reactions as well as transester...

Preparation of Diphenyl(tricyclohexylphosphine)manganese(II) and Its Reactions with Carbon Dioxide and Organic Carbonyl Compounds

Preparation of phenyl(acetylacetonato)nickel(II) complexes with tertiary phosphine ligands and their reactions with organic halogen compounds and olefins

Benzoyl(acetylacetonato)nickel(II) complexes containing tertiary phosphine ligands. Their synthesis, dynamic behavior in solution, and decarbonylation

New phenyl complexes, FePh2(PEt3)2 (1) and CoPh(acac)(PEt3)2 (2), were prepared by the reactions of [M(acac)3] (M = he and Co, respectively) with AIPh3 · Et2O in the presence of PEt3. Complex (1) is thermally unstable and decomposes above 0°, whereas the more stable complex (2) has m.p. 66–68°. Complexes (1) and (2) were characterized by means of microanalyses, i.r. spectroscopy, and some chemical reactions. Complex (1) reacted with carbon monoxide to give a high yield of benzophenone, while (2) gave only a small amount of cobaltcarbonyl species on reaction with carbon monoxide.

Preparation and properties of diphenyliron and phenylcobalt complexes with triethylphosphine ligands

A phenylchromium complex CrPh(acac)2 (1) (acac=2,4-pentanedionato ligand) was prepared from Cr(acac)3 and AlPh3·Et2O. Complex 1 reacts with acetone to give benzene, 2-phenyl-2-propanol, and mesityl oxide and is converted into a hydroxo complex [Cr(OH)(acac)2]2. The mechanism involving the insertion of the carbonyl group of acetone into the Ph–Cr bond giving an alkoxo intermediate is proposed. Reactions of 1 with esters proceed similarly to give diphenylmethanol derivatives and alkoxochromium complexes. Complex 1 reacts with ROH to give benzene and alkoxo complexes [Cr(OR)(acac)2]n [n=1 or 2) which were characterized by means of IR spectra, elemental analyses, molecular weight measurements, magnetic susceptibilities, and chemical reactions. The reactions of 1 with β-dicarbonyl compounds yield corresponding mixed chelate complexes Cr(β-dic)(acac)2, where β-dic=diethyl malonato and 1-ethoxy-1,3-butanedionato ligands.

Kazunori Maruyama

Papers

Preparation of Diphenyl(tricyclohexylphosphine)manganese(II) and Its Reactions with Carbon Dioxide and Organic Carbonyl Compounds

Preparation of phenyl(acetylacetonato)nickel(II) complexes with tertiary phosphine ligands and their reactions with organic halogen compounds and olefins

Benzoyl(acetylacetonato)nickel(II) complexes containing tertiary phosphine ligands. Their synthesis, dynamic behavior in solution, and decarbonylation

Preparation and properties of diphenyliron and phenylcobalt complexes with triethylphosphine ligands

Bis(2,4-pentanedionato)phenylchromium(III). Preparation and Reactions with Organic Carbonyl Compounds and Alcohols