1311484-52-2Relevant articles and documents
Synthesis, Structure and Reactivities of Pentacoordinated Phosphorus–Boron Bonded Compounds
Havare, Nizam,Kano, Naokazu,Morokuma, Keiji,O'Brien, Nathan J.,Ramozzi, Romain,Uematsu, Ryohei
, (2020/04/29)
The isolation and reactivities of two pentacoordinated phosphorus–tetracoordinated boron bonded compounds were explored. A highly Lewis acidic boron reagent and electron-withdrawing ligand system were required to form the pentacoordinated phosphorus state of the P–B bond. The first compound, a phosphoranyl-trihydroborate, gave a THF stabilised phosphoranyl-borane intermediate upon a single hydride abstraction in THF. This compound could undergo a unique rearrangement, which involved a two-fold ring expansion, to give a fused bicyclic compound or it could act as a mono-hydroboration reagent. The hydroboration reactivity of the intermediate was found to be higher towards alkynes vs. alkenes, with good to moderate regioselectivity towards the terminal carbon. The second compound, a phosphoranyl-triarylborate, was found to have different reactivity as it was highly stable towards acids and bases. This is thought to be due to the large bulk around the P–B bond as shown in the crystal structure.