In 1958, Leopold Horner published a modified Wittig reaction using phosphonate-stabilized carbanions.[2][3] William S. Wadsworth and William D. Emmons further defined the reaction.[4][5]
In contrast to phosphonium ylides used in the Wittig reaction, phosphonate-stabilized carbanions are more nucleophilic but less basic. Likewise, phosphonate-stabilized carbanions can be alkylated. Unlike phosphonium ylides, the dialkylphosphate salt byproduct is easily removed by aqueous extraction.
Several reviews have been published