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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 ...
Usually Grignard reagents are written as R-Mg-X, but in fact the magnesium(II) centre is tetrahedral when dissolved in Lewis basic solvents, as shown here for the bis-adduct of methylmagnesium chloride and THF. Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an ...
In organic chemistry, the Kumada coupling is a type of cross coupling reaction, useful for generating carbon–carbon bonds by the reaction of a Grignard reagent and an organic halide. The procedure uses transition metal catalysts , typically nickel or palladium, to couple a combination of two alkyl , aryl or vinyl groups .
In the original paper describing this reaction, methylmagnesium bromide is reacted with isophorone with and without 1 mole percent of added copper(I) chloride (see figure). [10] Without added salt the main products are alcohol B (42%) from nucleophilic addition to the carbonyl group and diene C (48%) as its dehydration reaction product.
Sodium sulfate is a typical electrostatically bonded ionic sulfate. The existence of free sulfate ions in solution is indicated by the easy formation of insoluble sulfates when these solutions are treated with Ba 2+ or Pb 2+ salts: Na 2 SO 4 + BaCl 2 → 2 NaCl + BaSO 4. Sodium sulfate is unreactive toward most oxidizing or reducing agents.
Alkyl sulfones may be reduced with sodium or lithium in liquid ammonia; [11] however, the strongly basic conditions of these dissolving metal reductions represent a significant disadvantage. In alcoholic solvents, magnesium metal and a catalytic amount of mercury(II) chloride may be used. [12]
The original reaction involved two subsequent substitutions: the conversion of an acid chloride with N,O-dimethylhydroxylamine, to form a Weinreb–Nahm amide, and subsequent treatment of this species with an organometallic reagent such as a Grignard reagent or organolithium reagent.
The identity of the metal, M, depends on which cross-coupling reaction is being used. Stille reactions use tin, Suzuki reactions use boron, Sonogashira reactions use copper, and Negishi reactions use zinc. The transmetalation step in palladium catalyzed reactions involve the addition of an R–M compound to produce an R′–Pd–R compound.