Convenient procedures for the synthesis of functionalized mono- and bisorganophosphorus acids and their derivatives with unsaturated and aromatic fragments, starting from the available derivatives of trivalent phosphorus acids, unsaturated and aromatic aldehydes, and carboxylic acid chlorides, are proposed, and some properties of the new unsaturated organophosphorus compounds are presented. (C) 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:3240, 2012; View this article online at . DOI 10.1002/hc.20749