Addition, cycloaddition, and metathesis reactions of the cationic carbyne complexes [Cp(CO)[sub 2]Mn[triple bond]CCH[sub 2]R][sup +] and neutral vinylidene complexes Cp(CO)[sub 2]M=C=C(H)R (M = Mn, Re)
- Pennsylvania State Univ., University Park, PA (United States)
- Laboratoire de Chimie de Coordination du CNRS, Toulouse (France)
- Univ. of Delaware, Newark, DE (United States)
The cationic alkylidyne complexes [Cp(CO)[sub 2]M=VCCH[sub 2]R][sup +] (M = Re, R = H; M = Mn, R = H, Me, Ph) undergo facile deprotonation to give the corresponding neutral vinylidene complexes Cp(CO)[sub 2]M=C=C(H)R. For [Cp(CO)[sub 2]Re=VCCH[sub 3]][sup +], this transformation occurs spontaneously at [minus]78[degree]C upon the addition of solvent (CH[sub 2]Cl[sub 2] or THF) to the solid carbyne complex, but the manganese complexes [Cp(CO)[sub 2]Mn=VCCH[sub 2]R][sup +] (R = H, Me) require the addition of external base (e.g., Et[sub 3]N) to induce their deprotonation. The manganese benzylcarbyne complex [Cp(CO)[sub 2]Mn=VCCH[sub 2]Ph][sup +] is intermediate in behavior. Except for Cp(CO)[sub 2]Mn=C=C(H)Ph, these vinylidene complexes are thermally unstable and must be generated and studied at low temperature. They are potent dipolarophiles which undergo net [2 + 2] cycloaddition with imines to give cyclic carbene complexes of the general form Cp(CO)[sub 2]M=CC(H)RC(H)PhN(R)[prime] (M = Re, R = H, R[prime] = Me, Ph; M = Mn, R[prime] = Ph, R = H (17a), Me, Ph (17c)). Identical manganese products form upon treatment of the manganese carbyne complexes first with imine followed by addition of Et[sub 3]N. Permanganate oxidation of the manganese cyclic carbene complexes gives the corresponding [beta]-lactams in excellent yield. Also formed in the reactions of the rhenium complex Cp(CO)[sub 2]Re=C=CH[sub 2] with imines are the products Cp(CO)[sub 2]Re=CC(=C(H)Ph)C(H)PhN(R[prime]) (R[prime] = Me, Ph (15b)), which have an exocyclic double bond formed via an aldol-type condensation between the initial cycloadduct and excess imine. 35 refs., 10 figs., 8 tabs.
- OSTI ID:
- 7267468
- Journal Information:
- Organometallics; (United States), Vol. 13:3; ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
MANGANESE COMPLEXES
CRYSTAL STRUCTURE
HYDROLYSIS
OXIDATION
ORGANOMETALLIC COMPOUNDS
CHEMICAL REACTIONS
RHENIUM COMPLEXES
ADDUCTS
AZINES
CARBON 13
CHEMICAL REACTION KINETICS
IMINES
LABELLED COMPOUNDS
LIGANDS
NITRILES
VINYLIDENE RADICALS
CARBON ISOTOPES
COMPLEXES
DECOMPOSITION
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
ISOTOPES
KINETICS
LIGHT NUCLEI
LYSIS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADICALS
REACTION KINETICS
SOLVOLYSIS
STABLE ISOTOPES
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
360602 - Other Materials- Structure & Phase Studies