Alkyl halides with Grignard reagents

Polarization also occurs in coupling and disproportionation reactions of Grignard reagents with alkyl halides. The vinyl protons of isobutene produced in the reaction of t-butylmagnesium chloride with t-butyl bromide show A/E polarization as do the methyl protons of isobutane (Ward et al., 1970). Similar results arise in the reaction of diethyl-magnesium with organic halides (Kasukhin et al., 1972). 

Scheme 29 Iron-catalyzed cross coupling reaction of aryl Grignard reagents with alkyl halides...

The perfluorohalogenomethylraercapto compound is formed in about 50% yield, the by-products being aryl halides from the Grignard reagent in 5-15% yield. It is assumed that the reaction follows an Sn2 mechanism with a cyclic intermediate state in analogy with the reaction of Grignard reagents with alkyl halides 98, 155), e.g.,... 

Coupling of alkyllithium and Grignard reagents with alkyl halides gives poor yields and if possible tends to produce mixtures of regio-and stereoisomers. However, effective procedures have been developed involving stoichiometric or catalytic use of Cu(I) salts.10 Thus, the copper-catalyzed substitution of iodide 7 by methallylmagnesium chloride 26 proceeds smoothly in 98 % yield. 

CO2). A partial solution to this problem is reaction of the vinyl Grignard reagent with alkyl halides in the presence of cuprous iodide [Cu(I)I], which does little for the initial loss of stereochemistry upon formation of... 

The coupling of alkyl groups by the reaction of Grignard reagents with alkyl halides to furnish higher alkanes is a well-established procedure (equation 95). The yields in many cases are not very heartening and products of cross coupling are also frequently... 

Kochi JK, Tamura M. Mechanism of the silver-catalyzed reaction of Grignard reagents with alkyl halides. J. Am. Chem. Soc. 1971 93(6) 1483-1485. 

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