Ethyl Grignard

The halogen influences the rate of reaction, and, in general, the order of reactivity is HI > HBi > HCl. Impoitant uses of etfiyl chloiide include the manufacture of tetraethyllead and ethylceUulose. Ethyl bromide can be used to produce ethyl Grignard reagent and various ethyl amines. 

Since the ethyl Grignard reagent is used in large excess, no special precautions need to be taken in the transfer to prevent the loss of small amounts. 

Ethyl Grignard added chorrosoloctivcly to acrolein (17) in good yield, but iso-propyl Grignard failed to give the reaction. The alternative straieg (6) was successful In this case. 

Reaction of m-chlorobenzonitrile with ethyl Grignard reagent produces ethylarylketone 191. Bromination in methylene chloride followed by displacement of the a-bromoketone moiety with t-butylamine... 

The (EtO)3Si0Si(0Et)3 could have been converted to Et3SiOSiEt3 with an ethyl Grignard reagent if desired (12). 

Sulfinyl aziridines (162) were found to undergo a clean metallation by ethyl Grignard with loss of the sulfoxide moiety to give the aziridinyl anions 163, which in turn can be alkylated in the presence of copper(I) iodide to give new elaborated products (164) with the heterocyclic nucleus intact <00TL6495>. 

The diketoindoles 777 were prepared in three steps starting from indol-3-ylacetic acid (680) and 5-chloro indol-3-ylacetic acid (774) in 75% and 66% overall yield, respectively. The indole acids 680 and 774 were converted into Weinreb amides 775, followed by reaction with ethyl Grignard reagent to afford the corresponding indol-3-yl ketones 776. In order to introduce the second carbonyl moiety, the 3-substituted... 

Germanium surface passivation by chloride termination inhibits oxide formation and maintains a well-ordered surface. The chloride-terminated surface can also be used as a reactive precursor for wet organic functionalization. For example, Cullen et al. [105] first demonstrated the reaction of a chloride-terminated Ge(lll) surface with ethyl Grignard as a means of ethylation for use in surface stabilization. The chlorination was performed by a mixture of Cl2 and HC1 gas with N2 above atmospheric pressures [105]. Although this resulted in approximately a one-to-one ratio of adsorbed chlorine atoms with Ge surface atoms, the high pressures resulted in severe etching of the substrate [105]. 

The original work on wet chemical functionalization of germanium was reported as early as 1962 by Cullen et al. (researchers in RCA labs) [105]. They exposed ethyl Grignard to a chloride-terminated Ge(lll) surface and used radiotracer studies with tritiated ethyl groups to show that ethylation of the surface occurs via formation of Ge—C bonds in a one-to-one ratio with surface atoms. Because the chlorination procedure used by the authors can lead to formation of mono-, di-, and trichloride species, there may be some uncertainty as to the Ge/C ratio. However, these surfaces did demonstrate hydrophobic behavior and stability in both atmosphere and aqueous solution. 

The target molecule has four carbon atoms, suggesting a route involving reaction of an ethyl Grignard reagent with ethylene oxide. 

Ethyl /3-oxovalerate, a Q-keto ester, is prepared from ethyl Grignard reagent and ethyl cyanoacetate (58%). Amino ketones are conveniently made by the action of aromatic Grignard reagents on y-diethyl-aminobutyronitrile, (CjH5)jNCHjCH2CHjCN, in 80-90% yields. ... 

The liquid, B.pt. about 100° C., fumes considerably in moist air, and with water gives silicopropionic acid and hydrogen chloride. The trichloride has also been obtained from silicon tetrachloride, using the ethyl Grignard reagent. It is a pale yellow, fuming liquid, B.pt. 97° to 103° C. 

The chloride must add in a conjugate fashion and the ethyl Grignard in a direct fashion that removes the carbonyl group. Conjugate addition can happen only if the carbonyl group is intact so must happen first and the lower suggestion will work. 

The most likely reaction course through the intermediary zircona-cyclopropane 11 and -cyclopentane 12 was proposed (Scheme 8) and could rationalize the loss of positional identity of both carbons of the ethyl Grignard reagent. Moreover, the origin of the aforementioned stereoselections [see Eqs. (18-20)] has been well explained in terms of chelation or steric repulsion in the intermediate species in this mechanism [70]. 

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