Organozinc Compound - Synthesis

Synthesis

Several general methods exist for the generation of organozinc compounds.

  • Oxidative addition. The original diethylzinc synthesis by Frankland was an oxidative addition of iodoethane to zinc metal with hydrogen gas as a "protective" blanket (this reaction is called the Frankland synthesis). The reactivity of zinc metal is increased in so-called Rieke zinc obtained by reduction of zinc chloride by potassium metal.
2RI + 2Zn → ZnR2 + ZnI2
  • Halogen zinc exchange. Two main halogen zinc exchange reactions are iodine zinc exchange and boron zinc exchange. The first step in the second procedure is hydroboration of an alkene:
  • Transmetalation. In a typical transmetalation, diphenylmercury reacts with zinc metal to diphenylzinc and metallic mercury in diethyl ether. Unfortunately, this reaction is slow, taking two weeks.
  • Organozinc compounds can be obtained directly from zinc metal:
In this method zinc is activated by the action of 1,2-dibromoethane and trimethylsilyl chloride. A key ingredient is lithium chloride which quickly forms a soluble adduct with the organozinc compound thus removing it from the metal surface.

Read more about this topic:  Organozinc Compound

Famous quotes containing the word synthesis:

    “It is in this impossibility of attaining to a synthesis of the inner life and the outward that the inferiority of the biographer to the novelist lies. The biographer quite clearly sees Peel, say, seated on his bench while his opponents overwhelm him with perhaps undeserved censure. He sees him motionless, miserable, his head bent on his breast. He asks himself: “What is he thinking?” and he knows nothing.”
    —Andre Maurois (1885–1967)

    “The new shopping malls make possible the synthesis of all consumer activities, not least of which are shopping, flirting with objects, idle wandering, and all the permutations of these.”
    —Jean Baudrillard (b. 1929)

    “If in the opinion of the Tsars authors were to be the servants of the state, in the opinion of the radical critics writers were to be the servants of the masses. The two lines of thought were bound to meet and join forces when at last, in our times, a new kind of regime the synthesis of a Hegelian triad, combined the idea of the masses with the idea of the state.”
    —Vladimir Nabokov (1899–1977)