Compound 2aa

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Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

General procedure for the synthesis of C-H alkylation/migration products 2: to a 10-mL oven-dried microwave vial containing a magnetic stirring bar was added anhydrous Cs₂CO₃ (488.7 mg, 1.5 mmol), the vial was then dried under vacuum with a heating gun for about 2 min. After cooling to room temperature, Pd(OAc)₂ (6.7 mg, 0.03 mmol), L7 (6.6 mg, 0.03 mmol), and 1 (if solid) (0.3 mmol) were added to the vial sequentially. The vial was then sealed with a re-sealable silicone/PTFE crimp cap, followed by three evacuation/Ar backfill cycle. After that, CH₃CN or ⁱPrCN (3 mL) and alkylating reagent 5 were added sequentially to the vial via the cap using syringe under argon (if substrate 1 is a liquid, it was dissolved in the solvent and added to the vial using syringe). The vial was degassed through three freeze−pump−thaw cycles before placing in a preheated oil bath at 90 ^oC. After the reaction was complete as monitored by TLC (24-72 h), the reaction mixture was allowed to cool to room temperature, diluted with ethyl acetate (20 mL), and filtered through a short pad of celite eluting with ethyl acetate (3×20 mL). After evaporation, the residue was purified by chromatography on silica gel (eluent: hexane or 1~2% ethyl ether in hexane) to afford the desired product 2.

The title compound 2aa was prepared according to the general procedure outlined above and obtained as a colorless oil: ¹H NMR (400 MHz, CDCl₃) δ = 7.62-7.56 (m, 1 H, Ar-H), 7.47-7.42 (m, 1 H, Ar-H), 7.33-7.23 (m, 2 H, Ar-H), 7.19-7.12 (m, 1 H, Ar-H), 7.11-7.04 (m, 2 H, Ar-H), 6.81 (t, J = 1.6 Hz, 1 H, C=CH), 3.99 (d, J = 1.6 Hz, 2 H, CH₂C=), 2.61-2.53 (m, 4 H, two CH₂ from n-Bu), 1.59-1.46 (m, 4 H, two CH₂ from n-Bu), 1.37-1.24 (m, 4 H, two CH₂ from n-Bu), 0.84 (t, J = 7.4 Hz, 6 H, two CH₃ from n-Bu); ¹³C NMR (100 MHz, CDCl₃) δ = 155.5, 142.3, 141.6, 134.4, 128.1, 127.2, 126.5, 124.2, 122.3, 120.3, 119.3, 111.4, 33.6, 33.1, 23.1, 22.8, 13.9; IR (CHCl₃, cm^-1) 2957, 2930, 2870, 2861, 1586, 1452, 1277, 1182, 1092; HRMS (DART) calculated for C₂₃H₂₉O [M+H⁺]: 321.22184, found: 321.22259.