Wittig Reactions of Trialkylphosphine-derived Ylides: New Directions and Applications in Organic Synthesis

The development of semi-stabilized, stabilized, and functionalized ylides derived from short-chain trialkylphosphines in the Wittig-type olefination reactions toward the synthesis of alkenes, including stilbenes, styrenes, and 1,3-dienes, as well as reagents for homologation reactions, are described. The methods allow easy access to alkenes with high (E)-stereoselectivity in good yield. These reactions are conducted with weak bases in aqueous media, which allows easy separation of water-soluble phosphine oxides. The development of a mild organocatalytic process for the Wittig reaction and extension toward the preparation of reporter stilbenes under biological conditions are also described. Applications toward the preparation of biologically active natural products and derivatives are discussed.