Search results
Results From The WOW.Com Content Network
Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH 3 and phenylmagnesium bromide (C 6 H 5)−Mg−Br. They are a subclass of the organomagnesium compounds.
A solution of a carbonyl compound is added to a Grignard reagent. (See gallery) An example of a Grignard reaction (R 2 or R 3 could be hydrogen). The Grignard reaction (French:) is an organometallic chemical reaction in which, according to the classical definition, carbon alkyl, allyl, vinyl, or aryl magnesium halides (Grignard reagent) are added to the carbonyl groups of either an aldehyde or ...
[7] [8] [9] The resulting reagent is then quenched with an electrophile. iPr 2 NMgCl·LiCl and TMPMgCl·LiCl react differently. The TMP-Turbo-Hauser base easily metalates ethyl-3-chlorobenzoate in the C2 position, while the same reaction carried out with the iPr-Turbo-Hauser base resulted in no metalation at all. Instead, an addition ...
The Hauser bases are prepared by treating a secondary amine with a Grignard reagent: R 2 NH + R′MgX → R 2 NMgX + R′H X = Cl, Br, I (:R 2 NH = diisopropylamine, TMP) Like many organolithium reagents, Hauser bases are generally used for metalation reagents. iPr 2 NMgBr selectively magnesiate carboxamides.
The Grignard reaction between phenylmagnesium bromide (1) and carbon dioxide in the form of dry ice gives the conjugate base of benzoic acid (2). The desired product, benzoic acid (3), is obtained by the following work-up: [2] Synthesis of benzoic acid with work-up step in red.
Ethylmagnesium bromide is a Grignard reagent with formula C 2 H 5 ... ethylmagnesium bromide may be used as a strong base to deprotonate various substrates such as ...
The addition of Grignard reagents to alkynes is facilitated by a catalytic amount of copper halide. Transmetalation to copper and carbocupration are followed by transmetalation of the product alkene back to magnesium. The addition is syn unless a coordinating group is nearby in the substrate, in which case the addition becomes anti and yields ...
The traditional method for generating the aryl Grignard reagent proceeds less predictably: slow, heterogeneous: XC 6 H 4 Br + Mg → XC 6 H 4 MgBr. Furthermore, traditional routes to Grignard reagents has limited functional group compatibility, whereas the Turbo-Grignard method tolerates other halides, some ester groups, and nitriles.