Abstract
Organophosphorus compounds are used as drugs, pesticides, detergents, food additives,
flame retardants, synthetic reagents, and catalysts, and their efficient synthesis
is an important task in organic synthesis. To synthesize novel functional organophosphorus
compounds, transition-metal-catalyzed methods have been developed, which were previously
considered difficult because of the strong bonding that occurs between transition
metals and phosphorus. Addition reactions of triphenylphosphine and sulfonic acids
to unsaturated compounds in the presence of a rhodium or palladium catalyst lead to
phosphonium salts, in direct contrast to the conventional synthesis involving substitution
reactions of organohalogen compounds. Rhodium and palladium complexes catalyze the
cleavage of P–P bonds in diphosphines and polyphosphines and can transfer organophosphorus
groups to various organic compounds. Subsequent substitution and addition reactions
proceed effectively, without using a base, to provide various novel organophosphorus
compounds.
1 Introduction
2 Transition-Metal-Catalyzed Synthesis of Phosphonium Salts by Addition Reactions
of Triphenylphosphine and Sulfonic Acids
3 Rhodium-Catalyzed P–P Bond Cleavage and Exchange Reactions
4 Transition-Metal-Catalyzed Substitution Reactions Using Diphosphines
4.1 Reactions Involving Substitution of a Phosphorus Group by P–P Bond Cleavage
4.2 Related Substitution Reactions of Organophosphorus Compounds
4.3 Substitution Reactions of Acid Fluorides Involving P–P Bond Cleavage of Diphosphines
5 Rhodium-Catalyzed P–P Bond Cleavage and Addition Reactions
6 Rhodium-Catalyzed P–P Bond Cleavage and Insertion Reactions Using Polyphosphines
7 Conclusions
Key words P–P bond cleavage - diphosphines - polyphosphines - addition reactions - exchange
reactions - insertion reactions - rhodium and palladium catalysts - organophosphorus
compounds
