background and overview[1][2]
2,3-dihydro-2-methylbenzofuran is an organic intermediate that can be prepared from 2-allylphenol.
preparation method[1-2]
1. cyrine ayed et al. reported that 2,3-dihydro-2-methylbenzofuran can be synthesized from the following raw material (e)-2-(prop-1-en-1-yl)phenol.
general procedure: add 0.1 mmol of styrene or its derivatives or olefins, photocatalyst (10 mg) to a glass vial equipped with an oxygen balloon containing 1.5 ml of solvent. a blue led lamp (460nm, 0.065wcm-2, osa opto light gmbh) was used as the light source. the reaction mixture was stirred at room temperature
temperature and irradiation for 18 hours. conversion and selectivity determined by gc-ms.
2. zhu x et al. reported the preparation of 2,3-dihydro-2-methylbenzofuran using 2-allylphenol under the action of catalyst ii.
to a 10 ml schlenk tube, add ii (0.0265 g, 0.025 mmol), dce (2.0 ml) and 2-allylphenol (0.10 ml, 1.0 mmol) under dry argon. the resulting mixture was stirred at 83°c for 24 hours. the reaction was cooled to room temperature and the catalyst was removed by filtration through a short pad of silica gel. product 2a was obtained by silica gel column chromatography using pentane/diethyl ether or petroleum ether/ethyl acetate as the eluent. the yield determined by gc using nonane as internal standard was 90%. 1h nmr (400 mhz, cdcl3): d ¼ 7.27e7.20 (m, 2 h), 6.97e6.89 (m,2 h), 5.05 e4.96 (m, 1 h), 3.41e3.35 (dd, j ¼ 15.6, 8.8 hz, 1 h), 2.93e2.87 (dd, j ¼ 15.2, 7.6 hz, 1 h), 1.58 (d, j ¼ 6.4 hz, 3 h). 13c nmr (100 mhz, cdcl3): d ¼ 154.5, 122.9, 121.9, 119.9, 115.1, 104.2, 74.3, 32.0, 16.7.
main reference materials
[1] cyrine a, lucas c d s, di w, et al. designing conjugated microporous polymers for visible light-promoted photocatalytic carbon-carbon double bond cleavage in aqueous medium[j]. journal of materials chemistry a, 2018:10.1039 .c8ta05772a-.
[2] zhu
