Tertiary phosphines: preparation and reactivity
The annual survey of the literature relating to the chemistry of tertiary phosphines, containing only P–C bonds, and published during 2019 is presented. The synthesis of new phosphines and phosphine reactivity, excluding metal complexation, are summarized and reviewed. The use of a wide range of tervalent phosphorus ligands in transition metal catalysis and in organocatalysis continues to be a major driver in the chemistry of traditional P–C-bonded phosphines which inspires the design of new phosphines of various structures and the tuning of their properties. As in recent years, a noteworthy feature of the literature reviewed is the large number of papers reporting studies of the reactivity of phosphines, in particular those involving nucleophilic attack at a carbon atom of an electrophilic substrate. Recent general reviews represent the current state of knowledge in the fields of the chemistry of phosphorus-centered polycyclic compounds and their applications, mainly in the field of design of optoelectronic materials, the chemistry of phosphorus-containing helicenes and helicenoids, the chemistry and the optoelectronic aspects of aromatic-fused diketophosphanyl compounds as promising scaffolds for functional organic materials and the design, complexing and catalytic properties of phosphorus-containing triazoles including the corresponding phosphines and their derivatives. Also reviewed is the diverse chemistry and applications of various types of polymer-supported triarylphosphines including both their use in metal complex catalysis and in metal-free organic reactions.