Phosphines, Transition Metal, Pincer, Catalysis
The epic growth of phosphines or phosphorus-based ligands oriented coordination chemistry and homogeneous catalysis is essentially due to their remarkable steric and electronic tunability and their ability to stabilize transition metals in low-valent and coordinatively unsaturated states. Despite they wear an “innocent mask”, their ability to control and modulate the electronic attributes of the metal centers makes them an integral part of homogeneous catalysis for a variety of organic transformations. Incorporation of pincer properties to the phosphine ligand systems has given much needed thermal stability to the metal complexes due to which chemical bonds such as C—C, C—O and C—H activation can be carried out efficiently. Synthesis of low-coordinate phosphorus compounds paved way for synthesizing several low-coordinated compounds of main group elements which give a new dimension to the chemistry of main group elements. Other phosphorus compounds such as phospholes, phosphoranes, phosphazanes with peculiar properties have also been studied extensively and they also find applications in sensors, molecular materials and supramolecular chemistry. The number of articles published on phosphines has grown from ~170 in 1966 to ~600+ in 2016 with the numbers exceeding 700s and 800s several times in the past, gives an estimate of its popularity and the number of groups working on it worldwide. To celebrate this remarkable feet of ‘phosphines in coordination chemistry’, I believe ICCC-43 is an appropriate occasion to host a thematic session on “Phosphorus Based Ligands: Coordination Chemistry and Catalysis” and listen to experts from different countries in Sendai in 2018.