6.05 Synthesis of Phosphonium Ylides

Abstract

The preparation of phosphonium ylides, the importance of which is obvious in different fields of chemistry including organic synthesis, medicinal chemistry, green chemistry, and materials science, was widely studied in the second half of the twentieth century. Nevertheless, the new green procedures, such as synthesis in water or under solvent-free conditions, applied to such common processes as, for example, proton abstraction from phosphonium salts or transformation of ylide precursors, offer new possibilities for target structure design. The works reported since the first edition of Comprehensive Organic Synthesis in 1991 also cover new synthesis routes to highly functionalized ylides, based on the addition of tertiary phosphines to a range of compounds including those bearing multiple bonds, modification of phosphorus ylides under the action of different reactants, and preparation of phosphorus ylides C-substituted by group 1–16 heteroatoms, thereby enlarging the scope of application of phosphorus ylides in synthetic organic and organometallic chemistry.