The Grignard reaction is an organometallic chemical reaction in which alkyl-
or aryl-magnesium halides (Grignard reagents) act as nucleophiles and attack
electrophilic carbon atoms that are present within polar bonds (e.g. in a
carbonyl group as in the example shown below) to yield a carbon-carbon bond,
thus altering hybridization about the reaction center.[1] The Grignard
reaction is an important tool in the formation of carbon-carbon bonds[2][3]
and for the formation of carbon-phosphorus, carbon-tin, carbon-silicon,
carbon-boron and other carbon-heteroatom bonds.
The nucleophilic organometallic addition reaction is irreversible due to the
high pKa value of the alkyl component (pKa = ~45). Such reactions are not
ionic; the Grignard reagent exists as an organometallic cluster (in ether).
The disadvantage of Grignard reagents is that they readily react with protic
solvents (such as water), or with functional groups with acidic protons, such
as alcohols and amines. In fact, atmospheric humidity in the lab can dictate
one's success when trying to synthesize a Grignard reagent from magnesium
turnings and an alkyl halide. One of many methods used to exclude water from
the reaction atmosphere is to flame-dry the reaction vessel to evaporate all
moisture, which is then sealed to prevent moisture from returning.
Grignard reactions and reagents were discovered by and are named after the
French chemist Francois Auguste Victor Grignard (University of Nancy, France)
who was awarded the 1912 Nobel Prize in Chemistry for this work
http://en.wikipedia.org/wiki/Grignard_reaction
其實我要說的是助教下課跟我說
炔的氫解離要加胺基鈉
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