Zinc methyl

Chemical Designations - Synonyms Zinc Dimethyl Zinc Methyl Methyl Zinc Chemical Formula (CH3)iZn. 

Nitro-compounds yield a series of reduction products accordmgto the nature of the reducing agent. Alkaline reducing agents sodium methylate, zinc dust and caustic soda, stannous chloride and caustic soda, produce azoxy, azo- and hydiazo-compounds. 

A related N-methylated zinc methoxide (323) also polymerizes cis- and trans- BO with inversion of stereochemistry. In this case, coordination of the monomer trans to the axial alkoxide is hindered by the N-Me group, so a modified mechanism has been proposed based on cis-coordination of the monomer, but which still involves the simultaneous participation of two metal centers. 

As Scheme 16 shows, vinyl(methyl)zinc compounds 17 were obtained from the hydrozirconation of terminal alkynes with Cp2ZrHGl, followed by treatment with dimethylzinc. The initially formed vinyl zirconium complex undergoes rapid transmetallation with ZnMe2 to yield the product.44... 

Dimethyl- and diethylzinc reacted with dimethylpyrrole- and mesityl-substituted cyclopentadiene ligands to give monocyclopentadienyl(methyl)zinc and -ethyl(zinc) compounds. These products then formed, Scheme 20, crystalline adducts with tetramethylethylenediamine (TMEDA) such as 24, whose solid-state structure is shown in Figure 11. 

Applying the usual steady-state treatment for consecutive first-order reactions kt at 16 torr pressure over the temperature range 597-701 °C is given by 1.8 x 1011 exp(—47,000/Kr) sec Within experimental error, reactions (1) and (2) were homogeneous processes. However, both k2 and k2 were functions of the total pressure in the system. This dependence is shown in Fig. 1. The methyl zinc decomposition is apparently in its second-order region. Therefore, assuming four effective oscillators and a mean temperature of 1050 °K, = Eohs.+i nRT... 

Reaction (5) may also occur in the reaction zone. However, the C6HjCH2-Zn bond should be somewhat weaker than the C6H5-Zn bond so that the benzyl-methyl zinc recombination may occur in a cooler region. Some dimerization of ZnCH3 probably also occurs. 

The overall process shown as reaction (14) is a necessary consequence of the observed CH3D/CH4 ratio. To be consistent with a ratio of unity, this reaction must proceed without the liberation of free methyl radicals and must account quantitatively for the fate of the methyl zinc. The exact nature of reaction (14) is unknown but several important observations have been made. Decomposition of Zn(CD3)2 with C6H12 in a vessel conditioned using Zn(CH3)2 produced the expected yield of CD4 indicating that the additional hydrogen needed for reaction (14) does not come from the coating on the conditioned vessel. Since reaction (15) cannot compete successfully under the experimental conditions used, it is doubtful if the reaction... 

The first cyclopentadienylzinc compound that was structurally characterized by an X-ray crystallographic study is cyclopentadienyl(methyl)zinc, Cp(Me)Zn (57) ". The structure of 57 in the solid state consists of puckered chains of methylzinc fragments, linked by bridging cyclopentadienyl groups (Figure 28). 

Bis[(dimethylisopropoxysilyl)methyl]zinc (74) has proven to be a valuable reagent in the nickel-catalysed cross-coupling reactions with alkenylsulfoximines, giving allylic silanes with complete retention of configuration. An X-ray crystal structure determination of 74 showed this compound to exist in the solid state as a coordination polymer (Figure 41). In 74, in addition to the two covalent Zn—C bonds [Zn—C(l) 1.953(7)... 

Another example is tetrameric methoxy(methyl)zinc, (MeZnOMe)4. The mechanism can be treated both as an aggregative process as well as a ligand coordination exchange process. It reveals aggregation due solely to oxygen bridging, with no direct participation of the C—Zn bond, and will be mentioned only briefly. 

Zinc Fluoborate Solution Zinc Fluoroborate Zinc Fluosilicate Zinc Hexafluorosilicate Zinc Methyl Zinc Nitrate... 

XANTHINE, 7-(5-HYDROXYHEXYL)-3-METHYL-l-PROPYL-XANTHINE, 3-ISOBUTYL-l-METHYL-ZINC OXIDE... 

Preparation of f>/s((S)-1-acetoxy-1-((1S,2S,4S,5S)-5-(4-pentenyl)-1-azabicyclo[2.2.2]oct-2-yl)methyl)zinc by boron-zinc exchange and its copper catalysed allylation preparation of 4-((S)-1-acetoxy-1-((1S,2S,4S,5S)-5-(4-pentenyl)-1-azabicyclo[2.2.2]oct-2-yl)methyl)quinoline12... 

Denmark et al. studied the effect of zinc iodide on the catalytic, enantioselective cyclopropanation of allylic alcohols with bis(iodomethyl)-zinc as the reagent and a bismethanesulfonamide as the catalyst 17]. They found significant rate enhancement and an increased enantiomeric excess of the product cyclopropane upon addition of 1 equivalent zinc iodide. Their studies and spectroscopic investigations showed that the Schlenk equilibrium appears to lie far on the left (IZnCHjI). Charette et al. used low temperature - C-NMR spectroscopy to differentiate several zinc-carbenoid species [18]. They also found evidence that in the presence of zinc iodide, bis(iodomethyl)zinc is rapidly converted to (io-domethyOzinc iodide. Solid-state structures of (halomethyl)zinc species have been described by Denmark for a bis(iodomethyl)zinc ether complex (6a) [19] and Charette for an (iodo-methyl)zinc iodide as a complex with 18-crown-6 (6b) [20] (Fig. 2). 

In an extensive study of the effect of experimental variables on the rate and selectivity of this reaction, Denmark et al. found the independent formation of ethylzinc alkoxide and bis(iodo-methyl)zinc to be crucial for effective cyclopropanation [34]. They also detected an autocataly-tic behavior of the reaction due to the generation of zinc iodide. 

Negishi coupling with methyl zinc chloride to regioselectively afford a trisubstituted benzo[3]furan 99, as illustrated in Scheme 53 <2002TL9125>. 

The reaction of diazomethane with zinc halides has been studied previously by several workers 70, 326, 475), and the formation of a zinc halide—methylene complex was suggested. Wittig and Schwarzen-bach 542) demonstrated the formation of iodomethylzinc iodide (I) and bis(iodomethyl)zinc (VIII) by the reaction of zinc iodide with diazomethane. The reaction of diazomethane with zinc chloride gives bis(chloro-methyl)zinc (IX) 544). 

Figure 18 Intermolecular coordination in the solid state bis [(dimethylisopropoxy silyl)methyl] zinc...

SOXINAL PZ SOXINOL PZ TRICARBAMIX Z TSIMAT TSIRAM (RUSSIAN) USAF P-2 VANCIDE MZ-96 ZERLATE ZIMATE ZIMATE METHYL ZINC BIS(DIMETHYLDITHIOCARBAMATE) ZINC BIS(DIMETHYLDITHIOCARBAMOYL)DISULPHIDE ZINC DIMETHYLDITHIOCARBAMATE ZINC N,N-DIMETHYLDITHIOCARBAMATE ZINCMATE ZINK-BIS(N,N-DIMETHYL-DITHIOCARBAMAAT) (DUTCH) ZINK-BIS(N,N-DIMETHYL-DITHIOCARBAMAi i (GERMAN) ZINKCARBAMATE... 

Two intermediate products of this reaction can be isolated, and they have been shown to have the composition CH3—Zn—I, methyl zinc odide and Zn(CH3)2, zinc methyl. The reactions are ... 

Methyl alcohol (small quantity). (excess). Zinc methyl methylate. Zinc methylate. Butlerow, Jahresber., 1864, p. 467. do. 

Fig. 5. Molecular structures of dimeric zinc bis[bis(trimethylsilyl)arsenide] (left) and trimcric methyl zinc bis(tri-methylsilyl)arsenide (right).

Mobile liquid. Stable in sealed tube and under C02. djfts 1.386 mp — 40° bp 46. Ignites in air, burrs with a blue flame, giving off a peculiar, garlic-like odor. Very slow oxidation with traces of air produces methyl zinc methylate, CHjZnOCHj. Sol in ether, miscible with hydrocarbons. 

---