ZIOC researchers have developed a general method for the synthesis of important organophosphorus building blocks
Organophosphorus compounds are widely used in medicine and agriculture. Over the past decades, great progress has been made in the field of carbon-phosphorus bond construction using metal-catalyzed transformations, as well as reactions under photoredox catalysis. However, there are still no versatile and convenient methods for the synthesis of N-containing organophosphorus compounds. However, structures containing both phosphorus and nitrogen atoms are found among drugs (fosazepam, brigatinib and fosenazid) and are also widely used in catalysis as ligands and in organic synthesis as building blocks of the Wittig reaction and its modifications.
In their recent study, scientists from the Laboratory of Organic and Metal-Organic Nitrogen-Oxygen Systems of the ZIOC managed to develop a general approach to the synthesis of β-hydrazonophosphine oxides, precursors of useful organophosphorus compounds, such as phosphorylated N-heterocycles, α-aminophosphonates, and vinylphosphonates. The method is based on the Michael addition of phosphine oxides to reactive azoalkenes (1,2-diaza-1,3-butadienes), which are formed directly during the reaction from α-halohydrazones and diisopropylethylamine as a base. The proposed approach is distinguished by a wide range of compatible substrates, mild reaction conditions, scalability, and stereoselectivity. Using strategies of chemoselective reduction of the C=N bond and deprotection/azine formation, the conversion of the obtained β-hydrazonophosphine oxides into potential chelating ligands was shown.
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