Visible Light Thiyl Radical‐Mediated Desilylation of Arylsilanes

Abstract

A straightforward, visible‐light triggered desilylation of arylsilanes by thiyl radicals is presented. Silyl groups are often used to block a reactive position in multi‐step organic synthesis, for which a mild cleavage at a late‐stage will provide new possibilities and disconnection routes by CAr−Si cleavage/deprotection. In this work, commercially available and cheap disulfides are employed for the first time in this type of C(sp2)‐Si bond cleavage reactions. Thus, upon irradiation with visible‐light, homolytic cleavage of the disulfide give rise to the corresponding thiyl radical that allows for a radical chain mechanism. This methodology represents a mild, fast and simple approach suitable for a broad variety of simply substituted arylsilanes. Moreover, the procedure could be easily extended to natural products and therapeutic derivatives, showing its robustness and synthetic application potential.

Lewis Acid‐Promoted Domino Processes for the Synthesis of Homoallylic Amines, Quinolines and Tetrahydroquinolines

“…1A** can result in the formation of Int. 7A via S N 1 pathway after the loss of hexamethyldisiloxane (observed in 29 Si NMR: δ=9.67 ppm, CDCl 3 ) [25] . DFT calculation revealed that the S N 1 is the favoured pathway (low energy of Int.…”

“…7A via S N 1 pathway after the loss of hexamethyldisiloxane (observed in 29 Si NMR: δ = 9.67 ppm, CDCl 3 ). [25] DFT calculation revealed that the S N 1 is the favoured pathway (low energy of Int. 6A) instead of the S N 2 pathway (because of the high energy of TS 1A), as shown in Figure 3.…”

Visible photons as ideal reagents for the activation of coloured organic compounds

“…This resulted in the formation of aryl radicals 31.4 and desilylated derivatives 31.3 from it through a HAT step (Scheme 31). 159…”