Preparation of Diversely Substituted Triarylmethyl Radicals by the Quenching of Tris(2,3,5,6‐tetrathiaaryl)methyl Cations with C‐, N‐, P‐, and S‐Nucleophiles

Abstract

C-, N-, P-, and S-nucleophiles reacted with symmetrical tris(2,3,5,6-tetrathiaaryl)methyl cations, generated from the corresponding triarylmethanols by strong acids, to give a variety of asymmetrical monosubstituted persistent triaryl-methyl (TAM) radicals as the major products. The only byproducts were symmetrical TAMs.

Development and Application of Spin Traps, Spin Probes, and Spin Labels

“…In most cases, trityls are not so easy to synthesize, but recently a convenient way of preparing Finland trityl (Rogozhnikova et al, 2013) and diversely substituted trityls were proposed (Scheme 8A), which is based on the quenching of tris(2,3,5,6-tetrathiaaryl)methyl cations by C-, N-, P-, and S-nucleophiles (Scheme 8B) (Tormyshev et al, 2014). The authors found that C-, N-, P-, and S-nucleophiles react with symmetrical tris(2,3,5,6-tetrathiaaryl)methyl cations generated from the corresponding triarylmethanols by strong acids.…”

Facile and High-Yielding Synthesis of TAM Biradicals and Monofunctional TAM Radicals

“…Despite this progress, surprisingly little has been reported on the synthesis of monofunctional trityl derivatives, 9 especially those which possess a specific reactive functional group to enable expanded use of TAMs. These monofunctional TAM derivatives enable the X substituent, Figure 1, to control properties of the TAM core, e.g.…”

“…9 In particular, the reaction of methyl thioglycolate with the cation 1 readily produced the functionalized TAM 2 (41%) along with two less-abundant byproducts – the unsubstituted TAM 3 and the quinonemethide 4 . This set of reactions is the basis for synthesis of one biradical.…”

“…9 Both paths start with addition of thiol to cation 1 to produce the intermediate 5 . The single-electron oxidation of 5 by cation 1 yields the unsubstituted symmetric TAM 3 10 and the desired monofunctional TAM 2 in the first path.…”

“…The oxidation of intermediate 5 by atmospheric oxygen during work-up of the final reaction mixture is the second path to 2 . 9 …”