Scope
The reaction can be extended to aliphatic aldehydes with base catalysis in the presence of thiazolium salts; the reaction mechanism is essentially the same. These compounds are important in the synthesis of heterocyclic compounds. The addition is also possible with enones; for instance methyl vinyl ketone is a reagent in the Stetter reaction.
In biochemistry, the coenzyme thiamine is responsible for biosynthesis of acyloin-like compounds. This coenzyme also contains a thiazolium moiety, which on deprotonation becomes a nucleophilic carbene.
In one study, a custom-designed N-heterocyclic carbene (NHC, the framework is related to thiazolium salts) was found to facilitate an enantioselective intramolecular benzoin condensation (Scheme 2).
This finding was confirmed in another study with a slightly modified NHC using DBU as the base instead of potassium tert-butoxide (Scheme 3).
Read more about this topic: Benzoin Condensation
Famous quotes containing the word scope:
“Each man must have his “I;” it is more necessary to him than bread; and if he does not find scope for it within the existing institutions he will be likely to make trouble.”
—Charles Horton Cooley (1864–1929)
“In the works of man, everything is as poor as its author; vision is confined, means are limited, scope is restricted, movements are labored, and results are humdrum.”
—Joseph De Maistre (1753–1821)
“Every person is responsible for all the good within the scope of his abilities, and for no more, and none can tell whose sphere is the largest.”
—Gail Hamilton (1833–1896)