Diazaphospholenes as reducing agents: a thermodynamic and electrochemical DFT study

Abstract

Diazaphospholenes have emerged as a promising class of metal-free hydride donors and have been implemented as molecular catalysts in several reduction reactions. Recent studies have also verified their radical reactivity...

Synthetic applications of NHPs: from the hydride pathway to a radical mechanism

“…16 Several theoretically computed values were acquired by Musgrave's group. 15 The experimental and theoretical E red [P + ]s covered a range of À2.52 V to À1.49 V. These extremely negative values further confirmed the excellent reducing capacity of NHP radicals, laying the foundation for their synthetic applications in radical reductions.…”

“…9 and eqn (1)). 16 Alkhater et al 15 estimated BDFEs for a series of NHPs by DFT calculations. These experimental and theoretical values are summarized in Fig.…”

“…1. 15 We summarized these Δ G H − and N values of NHPs herewith and placed them in the rectangular coordinates as shown in Fig. 2.…”

Diazaphospholene‐Catalyzed Radical Reactions from Aryl Halides**

“…[14] The diazaphospholene catalyst is readily made on a 40 gram scale, comparing favourably with more expensive metal-based or organic photocatalysts. [25] To gauge reducing ability, [27] we conducted cyclic voltammetry experiments on potentially relevant species 1, dimer 12 a, and phosphenium 13 (Scheme 4). These species showed complex and irreversible redox behavior, however a reduction wave was observed around À 1.75 volts vs. ferrocene/ferrocenium (Fc/Fc + ) for each compound and was strongest and cleanest for the phosphenium cation 13.…”

Guanidine-based biomimetic hydrides for carbon dioxide reduction

“…Recently, the groups of Glusac, 14,15 Musgraves 16,17 and Ostojić, 18 explored the use of benzimidazoles and diazaphospholenes as biomimetic hydrides to reduce CO 2 through computational and experimental studies (Scheme 1 middle). These systems are NADH analogues, whose reactivity are largely based on the amidine or amidine-like moiety.…”