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Haloalkane or alkyl halides are the compounds which have the general formula "RX" where R is an alkyl or substituted alkyl group and X is a halogen (F, Cl, Br, I). Haloalkanes have been known for centuries. Chloroethane was produced in the 15th century. The systematic synthesis of such compounds developed in the 19th century in step with the ...
In place of the halide reagent pseudohalides can also be used, and the coupling has been shown to be quite effective using tosylate [12] and triflate [13] species in variety of conditions. Despite broad success with aryl and vinyl couplings, the use of alkyl halides is less general due to several complicating factors.
Also, the best results for this test are observed in tertiary alcohols, as they form the respective alkyl halides fastest due to higher stability of the intermediate tertiary carbocation. The test was reported in 1930 and became a standard method in qualitative organic chemistry. [ 2 ]
Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents). [1] Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation.
This reaction was developed by Alexander Williamson in 1850. [2] Typically it involves the reaction of an alkoxide ion with a primary alkyl halide via an S N 2 reaction. This reaction is important in the history of organic chemistry because it helped prove the structure of ethers. The general reaction mechanism is as follows: [3]
Traditionally, the alkylating agents are alkyl halides. Many alkylating agents can be used instead of alkyl halides. For example, enones and epoxides can be used in presence of protons. The reaction typically employs a strong Lewis acid, such as aluminium chloride as catalyst, to increase the electrophilicity of the alkylating agent. [6]
In organic chemistry, the Menshutkin reaction converts a tertiary amine into a quaternary ammonium salt by reaction with an alkyl halide. Similar reactions occur when tertiary phosphines are treated with alkyl halides. Menshutkin-reaction. The reaction is the method of choice for the preparation of quaternary ammonium salts. [1]
This is consistent with initial attack of the phosphorus reagent on the alkyl halide as the rate-determining step of the reaction. The reaction proceeds smoothly when the R group is aliphatic. When all of A, B and R are aryl groups, a stable phosphonium salt is formed and the reaction proceeds no further under normal conditions.