p-Toluenesulfonic acid → (1S)-N-(cyclopropylmethyl)-1-(4-fluorophenyl)prop-2-en-1-amine

Participants

Reaction Steps

A mixture of (2E)-3-(4-fluorophenyl)prop-2-en-1-yl methyl carbonate (420 mg), N,N-bis[(1S)-1-phenylethyl]dinaphtho[1,2-f:2′,1′-d][1,3,2]dioxaphosphepin-4-amine (108 mg), [Ir(COD)Cl]2 (27 mg), cyclopropyl methyl amine (374 μL) and EtOH (5 mL) was stirred under refluxing EtOH for 6H under N2. The progress of the reaction was monitered by HPLC. At the end of the reaction, addition of co-solvent (20 ml EtOH and 20 ml THF) and MP-TsOH resin (6 g) and the mixture was allowed to stirred at RT with swilling every 15 mins for 2-3 hours. Filtered the resin and washed the resin with plenty of EtOH, THF, DCM. The resin was taken up in 3.5N NH3 in MeOH (20 mL) and let it stir for overnight. Filtered the resin and washed the resin excessively with EtOH, THF and DCM. Combined the filtrate and evaporated all the solvent. The crude product was purified by flash chromatography (10% EtOAc/Hexane) to afford the title compound as a viscous oil (350 mg, 88%). 1H NMR (300 MHz, CDCl3) revealed branched/linear ratio (9:1) 0.27 (m, 2H), 0.47 (m, 2H), 1.10 (m, 1H), 2.40 (m, 2H), 4.51(m, 1H), 5.25-5.39 (m, 3H), 7.02-7.22 (m, 4H). MS APCI, m/z=206 (M+1). LC/MS 0.85 min., Method A. 94% ee was determined by NMR in the presence of TFAE-d11

Provenance & Evidence