Organometallic Chemistry OGOSHI Lab.

AlMe₃-Promoted Oxidative Cyclization of η2-Alkene and η2-Ketone on Nickel(0). Observation of Intermediate in Methyl Transfer Process

S. Ogoshi, M. Ueta, T. Arai, and H. Kurosawa
J. Am. Chem. Soc.2005, 127, 12810-12811.
AlMe₃ can promote the oxidative cyclization of η2-alkene and η2-ketone on nickel(0) to give an intriguing nickel-aluminum dinuclear complex having a bridging Me group, which might be an intermediate for the nickel-catalyzed cycloisomerization of o-allylacetophenone or o-allylbenzophenone.

Direct Observation of Oxidative Cyclization of η2-Alkene and η2-Aldehyde on Ni(0) Center. Significant Acceleration by Addition of Me₃SiOTf

S. Ogoshi, M.-a. Oka, and H. Kurosawa
J. Am. Chem. Soc. 2004, 126, 11802-11803.
5-Hexenal derivatives can coordinate to a nickel(0) center, affording a series of η2:η2-5-hexenalnickel complex.
The η2:η2-5-enal complex undergoes intramolecular oxidative cyclization to form an oxanickelacyclopentane, and addition of Me₃SiOTf results in drastic acceleration of the cyclization reaction.

Dimerization of terminal alkynes catalyzed by a nickel complex having a bulky phosphine ligand

S. Ogoshi, M. Ueta, M.-a. Oka, and H. Kurosawa
Chem. Commun. 2004, 2732-2733.
Ni(cod)₂/P^tBu₃ system catalyzed the dimerization of terminal alkynes to give (E)-head-to-head dimerization products, in which the stannylacetylene dimer could be applied to a one-pot synthesis of a conjugated enyne, when combined with Migita-Stille coupling.

Stepwise growth of polypalladium chains in 1,4-diphenyl-1,3-butadiene sandwich complexes

Y. Tatsumi, T. Nagai, H. Nakashima, T. Murahashi, and H. Kurosawa
Chem. Commun. 2004, 1430-1431.
A series of multinuclear palladium sandwich complexes supported by two 1,4-diphenyl-1,3-butadiene molecules were prepared by stepwise growth of palladium chains within a sandwich framework. Reaction of palladium(I) dimer, [Pd₂(CH₃CN)₆][BF₄]₂ with PhCH=CHCH=CHPh afforded dipalladium complexes [Pd₂(μ-(1,2,3-η):(4,1',2'-η)-PhCH=CHCH=CHPh)(CH₃CN)₄][BF₄]₂.

Reaction of η²-enone and enal-platinum(0) complexes with Lewis acidic compounds

M. Morita, K. Inoue, T. Yoshida, S. Ogoshi, and H. Kurosawa
J. Organomet. Chem. 2004, 689, 894-898
Reaction of η²-enone and enal-Pt(0) complexes Pt(CH₂=CHCOR)(PPh₃)₂ (R = H, Me) with Lewis acidic compounds BX₃ (X = F, C₆F₅) afforded adducts formed by coordination of B to O of the carbonyl group.

Convenient synthesis of Pt(0) olefin complexes by colorimetric reduction of Pt(II) complexes with SmI₂

S. Ogoshi, M. Morita, K. Inoue, and H. Kurosawa
J. Organomet. Chem. 2004, 689, 662-665
Homoleptic olefin platinum(0) complexes, Pt(C₇H₁₀)₃ and Pt(cod)₂, were synthesized by the colorimetric reduction of platinum(II) complexes with SmI₂ in the presence of 2-norbornene or 1,5-cyclooctadiene.

Synthesis, Structure, and Reactivity of an η3-1-Hydroxyallyl Complex: Protonation of an α,β-Unsaturated Carbonyl Compound Bound to Palladium(0)and Platinum(0)

S. Ogoshi, M. Morita, and H. Kurosawa
J. Am. Chem. Soc. 2003, 125, 9020-9021
The direct addition of a proton to a carbonyl O in an η2-enone Pd complex led to the quantitative formation of η3-1-hydroxyallyl complexes [η3-(CH₂CHCR(OH))Pd(PPh₃)₂][CF₃SO₃] (R = H and Me).

Perylene-Tetrapalladium Sandwich Complexes

T. Murahashi, T. Uemura, and H. Kurosawa
J. Am. Chem. Soc. 2003, 125, 8436-8437
Bis-perylene-tetrapalladium sandwich complexes, which are the 1st examples of bis-arene sandwich complexes having metal-metal bond chains, were synthesized and structurally characterized.

Reaction of Palladium and Platinum Complexes Bearing α,β-Unsaturated Carbonyl Compounds with Carbon Electrophiles: Control over Site of Electrophilic Attack, Oxygen or Metal

M. Morita, K. Inoue, S. Ogoshi, and H. Kurosawa
Organometallics 2003, 22, 5468-5472.
The reaction of (η2-CH₂=CHCHO)M(dppf) (M = Pd, Pt) with methyl triflate yielded η3-methoxyallyl complexes [(η3-CH₃OCHCHCH₂)M(dppf)₂][OTf], and the η3-allyl moiety in these complexes is found to be distorted by X-ray diffraction study.

New direction in organopalladium chemistry: Structure and reactivity of unsaturated hydrocarbon ligands bound to multipalladium units

T. Murahashi, S. Ogoshi, and H. Kurosawa
Chemical Record 2003, 3, 101-111.

New chemistry of η³-allenyl/propargyl complexes of palladium and platinum

S. Ogoshi and H. Kurosawa
Yuki Gosei Kagaku Kyokaishi 2003, 61, 16-25.