Organozinc compounds. Part III. Further alcoholyses of dimethyl- and diphenyl-zinc

Abstract

Proton magnetic resonance spectroscopy of solutions obtained by treatment of dimethyl-and diphenyl-zinc with ethanol, propan-2-01. and 2-methylpropan-2-01 show that the monoethanolysis products are similar to the monomethanolysis ones described previously, but that the other alcohols yield simpler systems which are probably composed almost exclusively of aggregates of true organozinc alkoxides RZnOR'. The products from reactions with 2-methoxyethanol can also be formulated as true organozinc alkoxides, back co-ordination from the methoxyl oxygen atom to the zinc probably accounting for this difference from the ethoxide systems.The methylzinc n-dodecoxides and t-butoxides differ from the other systems in that the materials formed by treating the preformed zinc alkoxide with dimethylzinc are spectroscopically different from those obtained by direct monoalcoholysis.

Reactivity of C1 Surface Species Formed in Methane Activation on Zn‐Modified H‐ZSM‐5 Zeolite

“…[48][49][50] For example, Coates [51] et al showed that organometallic reagents are readily converted into hydrocarbons in the presence of water. Bruce [52] et al, Noltes and Boersma, [53] and Coates and Ridley [54] demonstrated that organozinc compounds can be transformed into organozinc alkoxide RZnOR' and hydrocarbons by alcoholysis. Furthermore, DFT calculations performed by Lambert [55,56] The organozinc nature of zinc methyl species on the Zn/ H-ZSM-5 catalyst has further been clarified in the reactions with oxygen and carbon dioxide.…”

“…showed that organometallic reagents are readily converted into hydrocarbons in the presence of water. Bruce52 et al., Noltes and Boersma,53 and Coates and Ridley54 demonstrated that organozinc compounds can be transformed into organozinc alkoxide RZnOR' and hydrocarbons by alcoholysis. Furthermore, DFT calculations performed by Lambert55, 56 et al.…”

“…The reactions of dimethyl-or diethylzinc with various compounds containing reactive hydrogen were investigated by Coates et al, [54] and followed by other groups. [52,53,55,56,76] Typical results obtained for the reactivity of organozinc compounds in organometallic chemistry are summarized in Scheme 4, in which the formation of hydrocarbons (R À H, such as methane) upon the reaction with water or alcohol was highlighted (Scheme 4 a and b). In our study, the reaction of zinc methyl species and oxygen on zeolite Zn/H-ZSM-5 produces surface formate species, surface methoxy species, and methanol, which may be mediated by the formation of a methyl peroxy species (Scheme 1 e).…”

Structural Organozinc Chemistry

“…The second important route involves the protonolysis of one of the alkyl or aryl groups of dialkyl-or diarylzinc compounds by an organic molecule containing an acidic proton bound to a heteroatom, e.g. alcohols 176,177 and primary 178 and secondary amines 176,179 . It is remarkable that one of the alkyl or aryl groups can be removed selectively.…”

Solid‐State Conversion of the Solvated Dimer [{tBuZn(μ‐OtBu)(thf)}2] into a Long Overlooked Trimeric [{tBuZnOtBu}3] Species

“…[…︁] Conclusive proof of the existence of alkylzinc alkoxide or aryloxide trimers still awaits a structural determination of such a compound ” 2a. Furthermore, the character of RZnOR species in noncoordinating solvents is a matter for conjecture, and studies on the aggregation state of [ t BuZnO t Bu] ( 1 ) are a classic example of inconsistency in the reported data: cryoscopic molecular weight studies by Coates and Roberts10 indicated that 1 exists as a mixture of dimers and trimers in benzene, whereas Noltes and Boersma11 concluded that only a trimer exists 12…”