Nascent-HBr-Catalyzed Removal of Orthogonal Protecting Groups in Aqueous Surfactants

Abstract

Organic reactions in the aqueous environment have recently emerged as a promising research area. The generation of nascent-HBr from the slow hydrolysis of the dispersed catalyst, benzyl bromide, with the interior water present in the hydrophobic core of the confined micellar medium in aqueous surfactant is described for the first time. The sustained-release nascent-HBr enabled the chemoselective cleavages of acid-sensitive orthogonal functionalities present in carbohydrates, amino alcohols, and hydroxylated acyclic compounds in good to excellent yields.

Synthesis of Dacus Pheromone, 1,7-Dioxaspiro[5.5]Undecane and Its Encapsulation in PLLA Microspheres for Their Potential Use as Controlled Release Devices

“…Benzyl bromide (0.7 mL, 6 mmol) was added dropwise to a stirring solution of potassium hydroxide (1.5 g; 26 mmol) in 1,4-butanediol (2.3 mL; 26 mmol) at room temperature and the mixture was further stirred at the same temperature for 3 h. Then, H 2 O (10 mL) was added and resulting mixture was extracted thrice with diethyl ether (3 × 50 mL). The combined organic layers were dried over MgSO 4 , the solvent was removed in a rotavapor and the resulting residue was purified by column chromatography (hexane/ethyl acetate 4:1) to afford 4.7 g of 4-(benzyloxy)butan-1-ol (1) as an oil (99% yield based on benzyl bromide), with spectral data identical to those reported in the literature [22] 1 H NMR (500 MHz, CDCl 3 ) δ 7.41-7.23 (m, 10H), 4.52 (s, 4H), 3.64 (t, J = 5.9 Hz, 4H), 3.52 (t, J = 5.8 Hz, 4H), 1.74-1.65 (m, 8H). 13 Synthesis of ((4-bromobutoxy)methyl)benzene (2).…”

New Route to Glycosylated Porphyrins via Aromatic Nucleophilic Substitution (SNAr)—Synthesis and Cellular Uptake Studies

“…The supporting information can be downloaded at: . References [ 26 , 60 , 61 , 62 , 63 ] are cited in the Supplementary Materials.…”