Ethylzinc iodide

Diazirines (3) smoothly add Grignard compounds to the N—N double bond, giving 1-alkyldiaziridines. Reported yields are between 60 and 95% without optimization (B-67MI50800). The reaction is easily carried out on a preparative scale without isolation of the hazardous diazirines and may serve as an easy access to alkylhydrazines. The reaction was also used routinely to detect diazirines in mixtures. The diaziridines formed are easily detected by their reaction with iodide. Phenyllithium or ethylzinc iodide also add to (3) with diaziridine formation. 

Eor ethylzinc chloride, CH3CH2ZnCl, and ethylzinc bromide, CH3CH2ZnBr, there is a linear relationship between the observed chemical shift and the ratio of ethylzinc halide to diethylzinc. Extrapolation of these lines to x=l (mol fraction of CH3CH2Z11X) gives predicted values for the average chemical shift that closely match those measured for these species. This indicates that for these two organozinc halides, the Schlenk equilibrium lies heavily on the side of the ethylzinc halide in toluene. However, in the case of ethylzinc iodide, CH3CH2ZnI, there is a... 

Charette et al. converted both primary and secondary alkyl iodides to the corresponding alkylzinc iodides, using either ethylzinc iodide or isopropylzinc iodide.34 The reactions, for example, Scheme 30, which were performed in UV-irradiated (X > 280 nm) chloroform solutions, gave conversions as high as 88% in less than 4h. 

Although O-alkyl-substituted enol ethers react smoothly with zinc carbenoids (eqna-tion 18) , higher yields are usually obtained with the Fnrnkawa reagent nsing a slight excess of diethylzinc to scavenge zinc iodide (and convert it into the less Lewis acidic ethylzinc iodide as it is formed) (see equation 18 vs 19). ... 

A modification to the original gem-dizinc protocol to improve the scope of the reaction was also reported. Ethylzinc iodide was used as the carbenoid precursor, and the reaction was run in the presence of zinc iodide. Under these conditions, simple aUylic ethers could be converted into iodo-cyclopropanes in high yields and diastereocontrol (equation 35). 

The first organometallic compounds of zinc, namely, ethylzinc iodide (EtZnI) and diethylzinc (Et2Zn), were... 

Figure 26 Part of the ethylzinc iodide polymer in the solid state...

This mobile fluid was diethylzinc, whereas the white mass of crystals contained both ethylzinc iodide and Znlg. Dimethylzinc was prepared in similar fashion (9S) ... 

Related reagent, ethyUodomethyliinc, QHjZnCHsl.12 Mol. wt. 235.38. The leagcnt is prepared by the reaction of ethyl iodide with zinc-copper couple in ihxoliite ether to give ethylzinc iodide (I). probably in equilibrium with diethyl-llttc and zinc iodide. This stock solution can be stored at room temperature for a... 

The resulting organozinc chloride is then treated with the acid chloride, giving up to 93% yields of ketone.357 For ketone syntheses by means of ethylzinc iodide see Morton, Davidson, and Newey.311... 

This type of compound is prepared by reacting arsenic hydrides with Grignard reagents, or in one case with ethylzinc iodide 212). 

In the solid state, apparently only one structure has been elucidated by X-ray diffraction. Thus, ethylzinc iodide, EtZnI, was found to contain polymeric chains, 1, in which each zinc atom forms two long (2.91 A) and one short (2.64 A) zinc-iodine bonds [2]. This leads to the formation of Zn h quasi-rings, which are interconnected in long chains. 

The reaction between a metal and an organic halogen compound provides a fairly general route to organometallic compounds. One of the earliest organometallic compounds ever to be prepared, ethylzinc iodide, was made in this way from zinc/copper couple and ethyl iodide. 

Ethylzinc chloride and bromide have tetrameric structures in the crystal, which are retained in solution in benzene. In contrast solid ethylzinc iodide forms polymeric chains. In all these structures zinc is four-coordinate. In ethers RZnX are monomeric through complex formation. 

Fig. 3.14 (a) Crystal structure of the ethylzinc iodide polymer. (After P.T. 

Figure 18. Crystal structure of the ethylzinc iodide polymor. (After P. T. Moseley and H. M. M. Shearer, Chem. Comm., 1966, 876).

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