Alkylmagnesium fluorides

Alkylmagnesium fluorides (3,159). The definitive paper on the preparation of alkyl-magnesium fluorides has now been published.6... 

Alkoxy-1,2,4,6,8-pentaazanaph thalenes, 431 Alkoxysulfonium fluoroborates, 78 a-Alkylacrylic adds, 301-302 N-Alkylanilines, 439 Alkylaiylacetylenes, 494 Alkylation of ketones, 30,64 2-Alkyl-1,3,2-benzodioxaboroles, 25 Alkylbenzohydroxamates, 389 OAlkylbenzohydroximoyl chlorides, 389 Alkylboronic add esters, 130 4-Alkyl-2-butene-l-ols, 53 2-Alkylcyclopentenones, 484 Alkyldichloroboranes, 130 2-r- Alkyl-1,3,2-dioxaborolanes, 69 Alkylene carbonates, 41 a-Alkylhydracrylic adds, 301-302 2-Alkylidenecydobutanols, 470 Alkylidene sulfones, 61 N-Alkylindoles, 246 Alkyl iodides, 336 Alkylmagnesium fluorides, 260... 

Alkylmagnesium fluorides.3 Alkylmagnesium fluorides have been prepared for the first time by reaction of alkyl fluorides (hexyl fluoride was used for the most part) with magnesium at reflux temperature in THF in the presence of various catalysts. Of these, iodine (4%) was found to be most effective the yield of Cirignard reagent was 95%, obtained in 6 days. Other less effective catalysts are cobalt chloride, bromine, ethylene dibromide, ethyl bromide. 

Full details of the preparation of alkylmagnesium fluorides are now available " (c/.Vol. 1, p. 87), and information on their structure and reactivity is also to hand. At last, phenylmagnesium fluoride has been prepared directly, albeit in poor yield the magnesium must be in the super-active form obtainable by alkali-metal reduction of anhydrous magnesium chloride or bromide in ether solvents. ... 

Interestingly, the first alkylmagnesium fluorides have been prepared in high yield by reaction of alkyl fluorides with magnesium in the presence of catalysts e.g. iodine) and by reaction of dialkylmagnesium compounds with boron trifluoride etherate both types of reaction are carried out in THF, and the latter can be applied to diphenylmagnesimn to provide phenylmagnesium fluoride. 

Scheme 5.61 Cu-catalyzed cross-coupling of alkylmagnesium reagents with alkyl fluorides and chlorides [127, 154].

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