Binap, (A+-)- → HCID 59352705, compound

Participants

Reaction Steps

To a solution of 1′-(4-bromobenzyl)-5,6-difluorospiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.44 g, 1.0 mmol) in anhydrous toluene (10 mL) was added (±)-(1,1′-binaphthalene-2,2′-diyl)bis(diphenylphosphine) (0.093 g, 0.15 mmol) and (R)-(+)-1-Boc-3-aminopyrrolidine (0.26 g, 1.4 mmol), followed by tris(dibenzylideneacetone)dipalladium (0) (0.458 g, 0.1 mmol) and sodium tert-butoxide (0.19 g, 2.0 mmol). The reaction mixture was heated at reflux for 16 h, allowed to cool to ambient temperature and filtered through a pad of diatomaceous earth. The filtrate was concentrated in vacuo and the residue dissolved in ethyl acetate (100 mL). The mixture was washed with water (2×75 mL) and brine (75 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by column chromatography and eluted with a 20% to 40% gradient of ethyl acetate in hexanes to afford tert-butyl (3R)-3-({4-[(5,6-difluoro-2′-oxospiro[1-benzofuran-3,3′-indol]-1′(2′H)-yl)methyl]phenyl}amino)pyrrolidine-1-carboxylate (0.403 g, 74%) as a brown oil: 1H NMR (300 MHz, CDCl3) δ 7.25-7.11 (m, 4H), 7.05-7.00 (m, 1H), 6.89 (d, J=7.7 Hz, 1H), 6.78 (dd, J=10.3, 6.3 Hz, 1H), 6.59 (s, 1H), 6.56 (s, 1H), 6.49 (dd, J=7.9, 7.9 Hz, 1H), 5.02-4.93 (m, 2H), 4.74-4.69 (m, 2H), 4.01 (br s, 1H), 3.76-3.68 (m, 2H), 3.46 (m, 2H), 3.20 (m, 1H), 2.21-2.12 (m, 1H), 1.87 (br s, 1H), 1.46 (s, 9H).

Provenance & Evidence