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RESEARCH PRODUCT
Cyclopentadienylmolybdenum(II) and -(III) complexes containing diene and allyl ligands. Part 4. Reactivity studies of the bisallyl complex CpMo(supine-η-C3H5)2 and the allyl-butadiene complex [CpMo(supine-η-C3H5)(supine-η-C4H6)] [PF6] .
Rinaldo PoliLi-sheng Wangsubject
Allylmagnesium bromideNucleophilic additionDiene010405 organic chemistryStereochemistryProtonation010402 general chemistry01 natural sciencesMedicinal chemistry0104 chemical sciencesInorganic ChemistryPropenechemistry.chemical_compoundchemistry13. Climate actionMaterials Chemistry[CHIM.COOR]Chemical Sciences/Coordination chemistryMethyllithiumReactivity (chemistry)Physical and Theoretical ChemistryCis–trans isomerismdescription
Abstract Compound CpMo( η 3 -C 3 H 5 ) 2 , 3, has been synthesized from CpMoCl 4 and four equivalents of allylmagnesium bromide. While the compound is stable in donor solvents at room temperature, warming in refluxing MeCN induces the formation of 1,5-hexadiene by a metal-mediated allyl-allyl coupling process. Treatment of 3 with Bu t NC at room temperature affords CpMo( η 3 -C 3 H 5 )(Bu t NC) 2 , 4. A similar reduction with presumed allyl radical loss occurs for [CpMo( η 3 -C 3 H 5 )( η 4 -C 4 H 6 )] + , [1c] + , to afford [CpMo( η 4 -C 4 H 6 )(Bu t NC) 2 ] + , 5. Treatment of [1c] + with methyllithium affords two products, the major one (1c) corresponding to the one-electron reduction pathway and the minor one (CpMo( η 3 -C 3 H 5 )( η 3 -C 3 H 4 -1-Et), 6, ca. 4%) corresponding to nucleophilic addition. Protonation of the 1c:6 mixture affords a 2:1 mixture of cis and trans 2-pentene, in addition to propene. The room temperature Cp 2 Fe + PF 6 − oxidation of 3 in MeCN induces the immediate release of 1,5-hexadiene. The oxidation of 3 in Bu t NC gives complexes [CpMo(CNBu t ) 3 ( η 2 −CH 2 CHCH 2 CH 2 CH=CH 2 )] + PF 6 − (7, major) and [ CpMo ( CNBu t ) 4 ] + PF 6 − (8, minor). Finally, the oxidation of 3 in the presence of butadiene, followed by treatment with CD 3 CN, affords a mixture of [ CpMo ( η 3 : η 3 − C 3 H 4 CH 2 CH 2 C 3 H 4 )(CD 3 CN)] + PF 6 − , 9, and [ CpMo ( η 4 − C 4 H 6 )(CD 3 CN) 2 ] + PF 6 − , 10. Thermal decomposition of this mixture affords butadiene and 1,5-cyclooctadiene.
year | journal | country | edition | language |
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1998-10-01 | Polyhedron |