Practical and Selective Bio-Inspired Iron-Catalyzed Oxidation of Si-H Bonds to Diversely Functionalized Organosilanols

Functionalized organosilanols have found wide applications pervading the realms of chemistry, material science, and medicine. However, a practical synthesis of structurally diverse organosilanols has remained elusive. Here, a bio-inspired nonheme-iron-catalyzed preparative oxidation of Si-H bonds of organo-silanes to diversely functionalized organosilanols with aqueous hydrogen peroxide as the oxidant at an iron catalyst loading of 0.1 mol % is reported. The practical and highly selective oxidation exhibits good functional group tolerance, allowing effective access to diversely functionalized alkyl-, aryl-, alkynyl-, and alkoxysilanols, silanediols, as well as mono-, oligo-, and polymeric siloxanols with various substituent patterns. Late-stage gram-scale application in functional-molecule-containing silanols is further demonstrated. Mechanistic studies suggest the involvement of high-valent Fe(V)oxo species and a sequence of hydrogen atom transfer and oxygen rebounds.