Visible-light-induced 1,2-diphenyldisulfane-catalyzed regioselective hydroboration of electron-deficient alkenes

Abstract

A green and practical photoinduced method for regioselective hydroboration of electron-deficient alkenes with NHC-borane has been developed in which 1,2-diphenyldisulfane was employed as photocatalyst and hydrogen atom transfer (HAT) reagent...

Photoredox dearomative β-hydroborylation of indoles for the synthesis of borylated indolines

“…Based on the above experimental results and previous reports, 17,21 a plausible mechanism for the visible-light-mediated dearomative β-hydroborylation of indole derivatives is proposed, as shown in Fig. 2.…”

“…16 Due to their low toxicity and ready availability, more and more researchers are starting to use Lewis base–borane as a boron reagent for the construction of C–B bonds, especially N-heterocyclic carbene-boranes (NHC-boranes). 17–20 Inspired by previous works on the dearomative hydroborylation of indoles 14 and our ongoing research interest in photochemical boron radical chemistry, 21 herein we report a visible-light-promoted dearomative β-hydroborylation reaction of indole derivatives and NHC-boranes, which provides an efficient route for preparing C2- or C3-borylated indolines (Scheme 1d).…”

Switchable Access to Mono‐ and Di‐Alkylated Boranes via Visible‐Light‐Induced Hydroboration of Alkenes with NHC‐Borane

“…Based on the above experiments and previous reports, [8e,9f,16] a potential mechanism for the hydroboration of alkenes with NHC borane was proposed (Scheme 4). For mono‐alkylation of NHC borane, homolysis of PhSSPh I under light irradiation generated a thiyl radical II which abstracted a hydrogen from NHC borane 2 to produce thiophenol III and NHC boryl radical IV .…”

Visible-Light-Enabled Radical Alkynylborylation of Activated Alkenes

“…According to the mechanistic studies experiments and previous work, 7,11 a plausible reaction mechanism is proposed in Scheme 5. Firstly, the photoexcited *Ir(ppy) 2 (dtbbpy)PF 6 undergoes single-electron oxidation of NHC-BH 3 (2a) to form intermediate 12, which can undergo a deprotonation process to furnish NHC-boryl radical 13.…”