Search results
Results from the WOW.Com Content Network
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 ...
Here, a strong Lewis acid is required to generate either a carbocation from an alkyl halide in the Friedel-Crafts alkylation reaction or an acylium ion from an acyl halide. In the vast majority of cases, reactions that involve leaving group activation generate a cation in a separate step, before either nucleophilic attack or elimination.
Methyl, ethyl, and other alkyl or aralkyl halides that are not dehydrohalogenated readily can react with aluminium in an exothermic process to form organoaluminium sesquihalides in high yields. An important example is the reaction of ethyl chloride with aluminium to form ethylaluminium sesquichloride. 3 C 2 H 5 Cl + 2 Al → (C 2 H 5) 3 Al 2 Cl 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]
The displaced halide anion then usually reacts via another S N 2 reaction on one of the R 1 carbons, displacing the oxygen atom to give the desired phosphonate (4) and another alkyl halide (5). This has been supported by the observation that chiral R 1 groups experience inversion of configuration at the carbon center attacked by the halide anion.
An acyl halide (also known as an acid halide) is a chemical compound derived from an oxoacid [1] by replacing a hydroxyl group (−OH) with a halide group (−X, where X is a halogen). [ 2 ] In organic chemistry , the term typically refers to acyl halides of carboxylic acids ( −C(=O)OH ), which contain a −C(=O)X functional group consisting ...
Such reactions are conducted in the presence of acidic catalysts. The other principal route to thiols involves the addition of hydrogen sulfide to alkenes. Such reactions are usually conducted in the presence of an acid catalyst or UV light. Halide displacement, using the suitable organic halide and sodium hydrogen sulfide has also been used. [23]
The reaction with alkyl halides leads to alkylation of the nitrogen atom. This creates a positive charge in the ring that increases the reactivity of pyridine to both oxidation and reduction. This creates a positive charge in the ring that increases the reactivity of pyridine to both oxidation and reduction.