Lipase-catalyzed resolution of β-hydroxy selenides

Abstract

Eleven b-hydroxy selenides were kinetically resolved using an immobilized lipase (Amano PS-C II) in toluene in the presence of vinyl acetate at 30°C. This approach provided, in several cases, both enantiomers in high enantiomeric excess. The role of the size of substituents and the behaviour of cyclic b-hydroxy selenides is also discussed. Enantiopure b-hydroxy selenides are useful building blocks. As an application of this chemistry, enantiopure (1S,2R)-indene oxide was obtained in one step from the proper enantiopure b-hydroxy selenide.

Iodosobenzene-Mediated Three-Component Selenofunctionalization of Olefins

“…13 C­{ 1 H} NMR (100 MHz, CDCl 3 ): δ 135.8, 134.54, 134.50, 128.1, 127.5, 127.2, 127.0, 126.6, 126.0, 125.4, 71.0, 47.6, 27.7, 26.5. Spectral data are in agreement with literature values …”

“…1 H NMR (400 MHz, CDCl 3 ): δ 7.61−7.46 (m, 2H), 7.33 (d, J = 7.9 Hz, 1H), 7.24−7.17 (m, 3H), 7.04−6.92 (m, 1H), 6.85 (d, J = 1.8 Hz, 1H), 4.82 (dt, J = 9.8, 2.9 Hz, 1H), 3.16 (dd, J = 12.9, 3.2 Hz, 1H), 2.96 (dd, J = 12.8, 9.8 Hz, 1H), 2.65 (d, J = 2.5 Hz, 1H), 2.22 (s, 3H), 2.03 (s, 3H). 13 40 anti-2-(Phenylselanyl)-2,3-dihydro-1H-inden-1-ol (3s). Compound 3s was prepared according to the general procedure and isolated as a white solid (62 mg, 86% yield) after flash chromatography (petroleum ether/ethyl acetate = 20:1).…”

“…Spectral data are in agreement with literature values. 40 1-Ferroceneyl-2-(phenylselanyl)ethan-1-ol (3x). Compound 3x was prepared according to the general procedure and isolated as an oil (64 mg, 66% yield) after flash chromatography (petroleum ether/ ethyl acetate = 10:1).…”

Copper-Catalyzed Oxirane-Opening Reaction with Aryl Iodides and Se Powder

“…Following the general procedure, after 12 h phenyl oxirane (144 mg, 3 equiv, 1.2 mmol) was added using a syringe, and using petroleum ether/ethyl acetate as the eluant afforded a yellow oily liquid (84.5 mg, 76% yield). The 1 H and 13 C NMR spectra were in accordance with those described in the literature …”

Biotransformations

“…The lipase Amino PS-C II was used to effect the resolution of bÀhydroxyselenides, again using vinyl acetate as the acyl donor, with E values ranging from 5 for 1-phenyl, 2-selanylethanol to greater than 200 for (R)-selective acylation of an anti-indenediol derivative, the latter being converted into enantiomerically pure indene oxide using oxone. 6 Epoxy enol esters have been resolved by lipase enzymes for the first time, in an effort to synthesise enantiomerically pure a-hydroxyaldehydes. 7 The enantioselective hydrolysis of 1-acetoxy-1,2-epoxycyclohexane by Candida rugosa lipase resulted in the resolution of the (+)-(S,S)-substrate and the production of (+)-(R)-2-hydroxycyclohexanone as a result of rearrangement of the hemiacetal that results from acetate hydrolysis.…”