1240405-56-4Relevant articles and documents
From silicon(II)-based dioxygen activation to adducts of elusive dioxasiliranes and sila-ureas stable at room temperature
Xiong, Yun,Yao, Shenglai,Mueller, Robert,Kaupp, Martin,Driess, Matthias
scheme or table, p. 577 - 580 (2010/10/04)
Dioxygen activation for the subsequent oxygenation of organic substrates that involves cheap and environmentally friendly chemical elements is at the cutting edge of chemical research. As silicon is a non-toxic and highly oxophilic element, the use of silylenes could be attractive for facile dioxygen activation to give dioxasiliranes with a SiO 2 -peroxo ring as versatile oxo-transfer reagents. However, the latter are elusive species, and have been generated and studied only in argon matrices at -233 °C. Recently, it was demonstrated that unstable silicon species can be isolated by applying the concept of donor-acceptor stabilization. We now report the first synthesis and crystallographic characterization of dioxasiliranes stabilized by N-heterocyclic carbenes that feature a three-membered SiO 2 -peroxide ring, isolable at room temperature. Unexpectedly, these can undergo internal oxygen transfer in toluene solution at ambient temperature to give a unique complex of cyclic sila-urea with C=O → Si=O interaction and the shortest Si=O double-bond distance reported to date.
