Isopropylmagnesium chloride

The conjugate addition of trichloromethylmagnesium chloride, prepared from 2.7 equivalents of isopropylmagnesium chloride and one equivalent of carbon tetrachloride at 110 C, to 8 (R1 = CH3) gave 9 with overall selectivity of 98 2 in 99% yield31. 

Aziridines have been opened by organometallic reagents to give amines. Although less reactive than epoxides, it is also possible to open aziridines with organometallic reagents. Isopropylmagnesium chloride reacts with A-tosyl 2-... 

The second cycloaddition substrate took to form of 91 (Scheme 1.9b), incorporating a vinyl sulfone dipolarophile. Beginning with cyano ketone 84, which was readily prepared from 1,5-dicyanopentane via a previously reported three-step sequence [45], condensation with thiophenol produced vinyl sulfide 85 in 84 % yield. Vinyl sulfide 85 underwent bromination in acetonitrile to afford bromo-vinyl sulfide 86 (86 %), which was then treated with isopropylmagnesium chloride [46] to effect metal-halogen exchange affording an intermediate vinyl magnesium bromide species. Subsequent alkylation with Mel in the presence of catalytic CuCN provided the alkylated vinyl sulfide 87 in 93 % yield. The nitrile within vinyl... 

A 500-ml., four-necked, round-bottomed flask is equipped with an efficient stirrer, a reflux condenser, a 250-ml. dropping funnel, and a low-temperature thermometer (Note 2). In the flask are placed 34.4 g. (21.8 ml., 0.25 mole) of phosphorus trichloride (Note 3) and 150 ml. of anhydrous ether. A solution of 0.50 mole of isopropylmagnesium chloride in about 150 ml. of ether (Notes 4 and 5) is placed in the dropping funnel. 

Chlorodiisopropylsilane, Cl(i-Pr)2SiH (1). The silane is prepared in 76% yield by reaction of isopropylmagnesium chloride with trichlorosilane. 

With unsubstituted 5-iodouracil 336, a trimagnesiated species 337 can be formed by sequential treatment with methylmagnesium chloride and isopropylmagnesium chloride, and reaction with various electrophiles then selectively gives 5-functionalized uracil derivatives 338 <20070L1639>. The same procedure was also successfully applied to the functionalization of 6-iodouracils, including the synthesis of Emivirine and l-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (ElEPT) precursors <20070L1639>. 

It should be noted that the sequence deprotonation/reverse Brook rearrangement between the triisopropylsilyloxy allene and isopropylmagnesium chloride in THE does not provide the magnesium enolate. 

In 2002, Figad re and coworkers reported the mono-reduction of 2-aryl (or heteroaryl)-1,1-dibromo-l-alkenes (Scheme 23). The reaction is achieved with one equivalent of isopropylmagnesium chloride in the presence of iron(III) acetylacetonate. Pure ( )-alkenyl bromides are obtained. With two equivalents of alkyl Grignard reagent, the mono-substituted product is obtained in moderate yield. 

Thus, a-sulfinyl lithium carbanion of 1-chloroethyl p-tolyl sulfoxide was reacted with 1,4-cyclohexanedione mono ethylene ketal (195) to afford the adduct (196) in quantitative yield. The adduct was treated with ferf-butylmagnesium chloride (magnesium alkoxide was initially formed) followed by isopropylmagnesium chloride to result in the formation of magnesium /3-oxido carbenoid 197. The /3-oxido carbenoid rearrangement then takes place to give one-carbon expanded magnesium enolate 198. Finally, an electrophile was... 

Treatment of 1-chloroalkyl phenyl sulfoxides with isopropylmagnesium chloride has been reported to yield magnesium carbenoids that also undergo 1,3-CH insertion to cyclopropanes (35) when a geminal methyl or benzyl group is present as in (34).36... 

Bromo-l-(4-fluorophenyl)-l-(3-dimethylaminopropyl)-l,3-dihydroisobenzofuran Magnesium Butyl lithium tert-Butyl methyl ether Isopropylmagnesium chloride Thionyl chloride Sulfamide Dry ice... 

The isopropyl compound V, (R = Me2CH) has readily been obtained from VI and isopropylmagnesium chloride in ether solution (94) but when R = cyclopentyl, THF has been found to be necessary for effecting the reaction. When R = tert-butyl the Grignard reaction yielded the dimer VII, but the desired V (R = er -butyl) has been obtained... 

To make any secondary alcohol, however, there is often a choice of two possible routes, depending on which part of the molecule you choose to make the organometallic and which part you choose to make the aldehyde. For example, the first example here shows the synthesis of a secondary alcohol from isopropylmagnesium chloride and acetaldehyde. But it is equally possible to make this same secondary alcohol from isobutyraldehyde and methyllithium or a methylmagnesium halide, acetaldehyde isobutyraldehyde... 

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