User:Bthsctt22/Williamson ether synthesis

My potential additions to the Williamson ether synthesis wiki page:

Mechanism
The Williamson ether reaction follows an SN2 bimolecular nucleophilic substitution mechanism. In an SN2 reaction mechanism there is a backside attack of an electrophile by a nucleophile and it occurs in a concerted mechanism (happens all at once). In order for the SN2 reaction to take place there must be a good leaving group which is strongly electronegative, commonly a halide.

In the Williamson ether reaction there is an alkoxide ion (RO-) which acts as the nucleophile, attacking the electrophilic carbon with the leaving group, which in most cases is an alkyl tosylate or an alkyl halide. The leaving site must be a primary carbon, because secondary and tertiary leaving sites generally prefer to proceed as an elimination reaction. Also, this reaction does not favor the formation of bulky ethers like di-tertbutyl ether, due to steric hindrance and predominant formation of alkenes instead.

Scope (to be added in this section)
The Williamson ether synthesis is a common reaction in the field of Organic Chemistry in industrial synthesis and in undergraduate teaching laboratories. Yields for these ether syntheses are traditionally low when reaction times are shortened, which can be the case with undergraduate laboratory class periods. Without allowing the reactions to reflux for the correct amount of time (anywhere from 1-8 hours from 50 to 100 °C) the reaction may not proceed to completion generating a poor overall product yield. To help mitigate this issue microwave-enhanced technology is now being utilized to speed up the reaction times for reactions such as the Williamson ether synthesis. This technology has transformed reaction times that required reflux of at least 1.5 hours to a quick 10-minute microwave run at 130 °C and this has increased the yield of ether synthesized from a range of 6-29% to 20-55% (data was compiled from several different lab sections incorporating the technology in their syntheses).

There have also been significant strides in the synthesis of ethers when using temperatures of 300 °C and up and using weaker alklylating agents to facilitate more efficient synthesis. This methodology helps streamline the synthesis process and makes synthesis on an industrial scale more feasible. The much higher temperature makes the weak alkylating agent more reactive and less likely to produce salts as a byproduct. This method has proved to be highly selective and especially helpful in production of aromatic ethers such as anisole which has increasing industrial applications.