Science of Synthesis Knowledge Updates 2021

Twenty-seven contributions have been published in 2021. These comprise:

A new chapter on the applications of chiral scandium complexes in asymmetric synthesis (W. Li, X. H. Liu, and X. M. Feng), highlighting the wide range of reactions in which these complexes can be applied as catalysts.
New chapters on the synthesis and applications of silylated germanes and silylated stannanes (J. A. Hlina). Wurtz-type couplings are particularly useful for the synthesis of these compounds, but several other reaction types can be used for the synthesis of more complex structures.
An update on the synthesis of pyranones and pyranthiones (F. V. Singh), which are important motifs in both natural products and synthetic molecules.
Updates on the synthesis of 1-(organochalcogeno)-2-(organooxy)alkenes, 1-nitrogen-functionalized 2-(organooxy)alkenes, and 1-phosphorus-functionalized 2-(organooxy)alkenes. That is, oxygen-substituted alkenes bearing phosphorus, nitrogen, sulfur, or selenium substituents on the other carbon atom of the alkene (J. Grimmer, S.-C. Krieg, and G. Manolikakes).
An update on the synthesis of cyclic phosphines (D. Gudat), covering secondary and tertiary phosphines with a phosphorus atom that is part of a saturated or partially unsaturated ring.
An update on phosphates and thiophosphates (B. A. Kashemirov, K. Błażewska, K. Justyna, J. Lyu, and C. E. McKenna), describing recent advances in the synthesis of both simple organic phosphates as well as nucleosides.