Sequential transformations have attracted much interest in recent years because they
provide simple and efficient entry into complex compounds by including two or more steps in a
single operation to increase the complexity of the substrate, starting from commercially
available, relatively simple precursors. The new methodologies discussed in this review chapter
are based on sequential transformations and possess high stereoselectivity. They include the
synthetic utility of fluorinated β-keto-phosphonium salts, “one-pot” carbon-carbon double bond
formation, ylide-ion formation resulting from nucleophilic addition, stereocontrolled olefination
method, alkenylation based on elimination of triphenylarsine, reductive olefination mediated by
Ti(O-i-Pr)4 and Ph3P and sequential transformation of organophosphorus compounds in organic
synthesis. The newly discussed methodologies are, therefore, potentially useful in organic
synthesis particularly in the medicinal and agricultural chemistry for the synthesis of
biologically active compounds.
