Five-Membered Rings With Two Adjacent Heteroatoms With at Least One Phosphorus, Arsenic, or Antimony

Chemistry of five-membered heterocycles containing two adjacent heteroatoms, with at least one phosphorus, arsenic or antimony, is reviewed. Species possessing 6 π-electrons are included only, which requires that at least one of the pnictogen (P, As, Sb) ring atom is two coordinate. Both neutral and anionic species are included. The timespan covered is 2008–20, with some references from 2007. Structural (single crystal X-ray diffraction) and theoretical studies of these compounds are discussed, with a number of 31P NMR data listed. The reactivity and synthesis are systematically covered. The reactivity is dominated by cycloadditions and coordination chemistry, with 1,2-diphospholes, 1,2-diphospholides, 1,2-azaphospholes and 1,2-azaarsoles dominating this area of chemistry.