Original TDAE strategy using α-halocarbonyl derivatives

Organic Electron Donors as Powerful Single‐Electron Reducing Agents in Organic Synthesis

“…[86c,e,f] Nucleophile substitutions were also explored by using electrophiles containing a C sp3 À halogen bond (Scheme 22, Figure 5). [90] The reaction of o-nitrobenzyl chlorides with various a-haloesters and a-haloamides, although less reducible than the benzyl chlorides but sufficiently electrophilic, led to the expected substitution products 100 in moderate to high yields (23-92 %). The yields decreased when less-labile bromocarbonyl groups were used and as the steric hindrance of the alkyl groups was increased (R 1 , Figure 5).…”

Original TDAE Strategy Using Propargylic Chloride: Rapid Access to 1,4-Diarylbut-3-ynol Derivatives

“…Reducing the temperature of stage 1 (−20 °C to −50 °C; Entry 8) did not change diarylbutynol yields, but did improve the treatment of the reaction. Recently, we showed that the temperature of stage 2 affects TDAE reactivity in the o -nitrobenzylic series [ 30 ]. Thus, in Entry 9 the reaction was stirred under 60 °C for 2 h in stage 2 and diarylbutynol 4a was obtained in 65% yield.…”

Evolution of neutral organic super-electron-donors and their applications

“…It is also true that, compared to sulfur, nitrogen atoms would have better orbital overlap with adjacent carbon atoms due to similar size, thus leading to greater aromaticity in the oxidised forms of the analogous electron donors. Dolbier and Médebielle et al, 26 Vanelle et al, 27 and Nishiyama et al 28 reported the use of commercially available TDAE [tetrakis(dimethylamino)ethylene] 24 as an electron donor for the reduction of various halide compounds. The first oxidation potential of 24 is -0.78 V vs. SCE and -0.61 V vs. SCE for the second in MeCN 29 and this manifests the higher reducing power of 24 over TTF 1 and diazadithiafulvalenes 23.…”