| Yamaguchi esterification | |
|---|---|
| Named after | Masaru Yamaguchi |
| Reaction type | Coupling reaction |
| Identifiers | |
| Organic Chemistry Portal | yamaguchi-esterification |
| RSC ontology ID | RXNO:0000309 |
TheYamaguchi esterification is thechemical reaction of analiphaticcarboxylic acid and2,4,6-trichlorobenzoyl chloride (TCBC, Yamaguchi reagent) to form a mixedanhydride which, upon reaction with analcohol in the presence of stoichiometric amount ofDMAP, produces the desiredester. It was first reported by Masaru Yamaguchiet al. in 1979.[1][2]
It is especially useful in the synthesis of macro-lactones and highly functionalised esters.
The aliphatic carboxylate adds to the carbonyl carbon of Yamaguchi reagent, forming a mixed anhydride, which is then attacked by DMAPregioselectively at the less hindered carbon, producing acyl-substituted DMAP. This highlyelectrophilic agent is then attacked by the alcohol to form the product ester.
Thein situ formation of the symmetric[clarification needed] aliphatic anhydride is proposed to explain the regioselectivity observed in the reactions of aliphatic acids, based on the fact that aliphatic carboxylates are more nucleophilic, and aliphatic anhydrides are more electrophilic towards DMAP and alcohol than their counterparts.[clarification needed]