Trialkoxysilane Exchange: Scope, Mechanism, Cryptates and pH‐Response

Abstract

The dynamic covalent chemistry (DCvC) of the SiÀ O bond holds unique opportunities, but has rarely been employed to assemble discrete molecular architectures. This may be due to the harsh conditions required to initiate exchange reactions at silicon in aprotic solvents. Herein, we provide a comprehensive experimental and computational account on the reaction of trialkoxysilanes with alcohols and identify mild conditions for rapid exchange in aprotic solvents. Substituent, solvent and salt effects are uncovered, understood and exploited for the construction of silaorthoester cryptates. A sharp, divergent pH-response of the obtained cages renders this substance class attractive for future applications well beyond host-guest chemistry, for instance, in drug delivery.

p-Block Element Catecholates: Lewis Superacidic, Constitutionally Dynamic, and Redox Active

“…It is important to note the absence of protons in the exchange, which thus substantially differs from Si-OR/HO-R' exchange under protic conditions. [38] We also added the first spectroscopic evidence for the spontaneous occurrence of a direct Si-O σ-bond metathesis, thus shedding light on the dynamic constitutional nature of the most common chemical bond in the Earth's crust. These insights have implications for catalysis, environmental and materials science:…”