Transition metal butadienyl complexes

New diruthenium vinyliminium complexes from the insertion of alkynes into bridging aminocarbynes

“…Xyl Me 21 Scheme 10. relative to the coordination to Ru(1) perfectly resemble the ones previously reported for other 1,2,3-g 3 butadienyl complexes [10]. Finally, the C (13) Finally, the reaction of 7b with NaH results in the formation of the tetranuclear complex [Ru 2 {l-g 1 :g 2 -C(Me)CCN(Me)(Bz)}(l-CO)(CO)(Cp) 2 ] 2 (23) in moderate yields (56%) (Scheme 13).…”

“…1, whereas the main bond lengths and bond angles are reported in Table 1. The structure of 2a is equivalent to that previously reported for the analogous diiron complex [Fe 2 {l-g 1 :g 3 -C(SiMe 3 )@CHC@ N(Me)(Xyl)}(l-CO)(CO)(Cp) 2 ] + (10) and also in this case it can be discussed with reference to three different resonance forms (Scheme 4). The C (13) In general, interconversion between the E and Z forms has not been observed for any of the Ru-species described in this paper neither for the analogous iron complexes previously reported [1].…”

Effect of substituents on the molybdenum mediated carbonylation and methoxycarbonylation of dihaloalkynes

“…Anhydrous conditions and inert atmospheres are often essential however, because sensitivity of reactants or organometallic intermediates to moisture and air can limit the purity and yield of products [1]. In a previous publication, the author with others reported the first clean synthesis in good yield of an g 3 -butadienyl complex by reaction of [Mo(CO) 3 (phen)Cl] À and 1,4-dichloro-2-butyne in water [2]. The acyl chloride substituent in [MoCl(CO) 2 (g 3 -CH 2 C(COCl)C@CH 2 )(phen)] was considered to have arisen by insertion of molecular CO into a metal-allenyl intermediate, followed by chloride attack and rearrangement to form the product.…”

“…The acyl chloride substituent in [MoCl(CO) 2 (g 3 -CH 2 C(COCl)C@CH 2 )(phen)] was considered to have arisen by insertion of molecular CO into a metal-allenyl intermediate, followed by chloride attack and rearrangement to form the product. Complexes containing the g 3 -butadienyl ligand are important, because of their relationship to metal-coordinated g 2 -alkenes and g 4 -dienes, their relative ease of conversion to g 3 -allyls and their relevance to organic synthesis [3]. Reports that g 3 -butadienyl complexes of palladium and iridium containing terminal substituents are key intermediates in certain catalytic processes has provided an additional incentive to explore the scope of our carbonylation reactions more widely [4,5], in particular to investigate the influence of alkyne substituents upon successful carbonylation in different solvents.…”

“…Reports that g 3 -butadienyl complexes of palladium and iridium containing terminal substituents are key intermediates in certain catalytic processes has provided an additional incentive to explore the scope of our carbonylation reactions more widely [4,5], in particular to investigate the influence of alkyne substituents upon successful carbonylation in different solvents. Dihaloalkynes of the type YCH(R)C"CCH(R)Y or YCR 2 C"CCR 2 Y were therefore synthesized using variations of literature methods, and reactions with nucleophilic anions [Mo(CO) 3 (phen)Y] À were investigated in organic solvents and water. This publication describes the influences of halogen and degree of alkyne substitution on the type and stability of product formed.…”