School of Perfume and Aroma Technology, Shanghai Institute of Technology, 100 Haiquan Rd., Shanghai 201418, P. R. of China eMail: liufeng@sit.edu.cn
› InstitutsangabenThis work was supported by the National Natural Science Foundation of China (Grants 21302126). The authors also thank Shanghai Municipal Education Commission and Shanghai Institute of Technology for financial support.
Polysubstituted 3-chalcogenated indoles were synthesized by a three-component, one-pot, domino reaction of a N-(2-bromophenyl)trifluoroacetamide, a 1-alkyne, a disulfides or diselenides, CuI, and proline in DMF. In this process, tandem Sonogashira coupling, N-cyclization, and sulfenyl/selenyl electrophilic substitution occurred sequentially and smoothly to form the anticipated products in good to excellent yields (20 examples; 65–96%). Notably, no palladium catalyst was used in this catalytic system, supporting its cost effectiveness and potential industrial application.
2a
Kolasa T,
Gunn DE,
Bhatia P,
Woods KW,
Gane T,
Stewart AO,
Bouska JB,
Harris RR,
Hulkower KI,
Malo PE,
Bell RL,
Carter GW,
Brooks CD. W.
J. Med. Chem. 2000; 43: 690
2b
Ragno R,
Coluccia A,
Regina GL,
De Martino G,
Piscitelli F,
Lavecchia A,
Novellino E,
Bergamini A,
Ciaprini C,
Sinistro A,
Maga G,
Crespan E,
Artico M,
Silvestri R.
J. Med. Chem. 2006; 49: 3172
2c
La Regina G,
Edler MC,
Brancale A,
Kandil S,
Coluccia A,
Piscitelli F,
Hamel E,
De Martino G,
Matesanz R,
Diaz JF,
Scovassi AI,
Prosperi E,
Lavecchia A,
Novellino E,
Artico M,
Silvestri R.
J. Med. Chem. 2007; 50: 2865
112-Phenyl-3-(phenylthio)-1H-indole (3a); Typical ProcedureA sealable reaction tube equipped with a magnetic stirrer bar was charged with 2-N-(2-bromophenyl)-2,2,2-trifluoroacetamide (1ab; 1 mmol), ethynylbenzene (2a; 1 mmol), Ph2S2 (0.5 mmol), Cs2CO3 (2 mmol), CuI (0.1 mmol), proline (0.3 mmol), and DMF (2 mL). The reaction vessel was placed in an oil bath at 100 °C under N2, and the mixture was stirred at this temperature for 12 h. The cap was then opened and the mixture was stirred at the same temperature for another 12 h. It was then cooled to r.t., diluted with EtOAc, and washed with H2O and brine, then dried (MgSO4) and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, hexane–EtOAc (10:1)] to give a pale-yellow solid; yield: 265 mg (88%); mp 139–141 °C.1H NMR (500 MHz, CDCl3): δ = 8.56 (s, 1 H), 7.80 (d, J = 7.2 Hz, 2 H), 7.71 (d, J = 7.9 Hz, 1 H), 7.48 (m, 3 H), 7.42 (t, J = 7.2 Hz, 1 H), 7.33 (t, J = 7.5 Hz, 1 H), 7.21 (m, 3 H), 7.17 (d, J = 7.5 Hz, 2 H), 7.10 (t, J = 7.2 Hz, 1 H). 13C NMR (125 MHz, CDCl3): δ = 140.84, 139.11, 135.97, 134.65, 131.20, 129.83, 129.42, 129.05, 125.71, 124.98, 123.66, 121.47, 120.10, 111.45, 99.97. HRMS (ESI): m/z [M + Na]+ calcd for C20H15NNaS+ = 324.0817; found: 324.0819.
