C3-triiodocyclotriveratrylene as a key intermediate to fluorescent probes: application to selective choline recognition

Abstract

A new strategy to obtain fluorescent cyclotriveratrylene (CTV) probes is proposed. The key intermediate, a triiodo CTV, is prepared in 3 steps with 47% overall yield. The whole synthesis requires only one purification step. The potential of this triiodo CTV as an intermediate is illustrated through the synthesis of a fluorescent phosphorylated probe that is able to bind choline and acetylcholine in pseudo-physiological conditions, with selectivity towards choline. As a consequence, this intermediate should allow us to rapidly form a library of probes in order to highlight the most promising ones.

Generation of Cryptophanes in Water by Disulfide Bridge Formation

“…As shown in Scheme , the synthesis of cyclotris(2‐mercaptomethyl)phenolene 1 H 6 started from the known triiodo‐CTB derivative 3 , which was obtained in four steps from 3‐hydroxybenzoic acid in 23 % overall yield. Halogen/metal exchange was carried out by the reaction of 3 with n BuLi at –78 °C, as reported in the literature.…”

“…Other solvents and reagents were used as received. Compounds 3 and 4 [4c] were synthesized according to the literature. Deuteriated bases were obtained by dissolution of commercial bases in D 2 O followed by solvent evaporation.…”

Synthesis of Cyclotriveratrylene–Phenylacetylene Derivatives and a Photophysical Investigation of Rigid Conjugated Cyclotriveratrylene Dendrimers

“…In contrast to the method developed by Gosse, [13] NaBH 4 was used to reduce propyl or butyl ester intermediate without deiodination instead of diisobutylaluminum hydride, which was used at -80°C. Treatment of 2a and 2b with P 2 O 5 and Et 2 O under reflux gave the cyclotribenzylene compounds 3a and 3b, which could be purified by recrystallization from CHCl 3 / hexane.…”

“…Further study showed that the more reactive indolylphosphane ligand was required. Gosse [13] reported an efficient route to synthesize the same CTV-I 3 starting from 3-hydroxy-4-iodobenzoic acid in three steps with 47 % overall yield. Collet reported the synthesis of CTV-I 3 in 1995.…”

“…1 H NMR (400 MHz, CDCl 3 ): δ = 7.69 (d, J = 11.2 Hz, 1 H), 6.81 (d, J = 11.2 Hz, 1 H), 6.66-6.63 (m, 1 H), 4.60 (s, 2 H), 4.00 (t, J = 11.8 Hz,2 H), 1.83-1.79 (m, 2 H), 1.58-1.52 (m, 2 H), 0.99 (t, J = 14.8 Hz, 3 H) ppm 13. 1 H NMR (400 MHz, CDCl 3 ): δ = 7.71 (d, J = 8.0 Hz, 1 H), 6.83 (s, 1 H), 6.68-6.66 (m, 1 H), 4.64 (d, J = 4.8 Hz, 2 H), 3.98 (t, J = 12.8 Hz,2 H), 1.90-1.81 (m, 2 H), 1.09 (t, J = 15.2 Hz, 3 H) ppm.…”