Figure 3: Probe SFP-2 synthesis.
From: Selective fluorescent probes for live-cell monitoring of sulphide
(a) RuCl2(PPh3)3 (0.7% equivalent), HCOOH (2.8 equiv.), Et3N (1.7 equiv.), THF, 25 °C, 2 h, 92%; (b) TBSCl (1.2 equiv.), imidazole (2 equiv.), DMF, 25 °C, 12 h, 99%; (c) NaBH4 (10 equiv.), 1, 4-dioxane/H2O (3:2), 65 °C, 12 h, 72%; (d) PCC (1.5 equiv.), celite, CH2Cl2, 25 °C, 1 h, 64%; (e) (1) 2,4-dimethylpyrrole (2 equiv.), TFA (one drop), CH2Cl2, 25 °C, 12 h. (2) DDQ (1 equiv.), CH2Cl2, 25 °C, 1 h. (3) DIPEA (10 equiv.), BF3·Et2O (30 equiv.), CH2Cl2, 25 °C, 2 h, 58%; (f) TBAF (1 equiv.), THF, 25 °C, 30 min, 83%; (g) PCC (5 equiv.), MgSO4, CH2Cl2, 25 °C, 30 min, 65%; (h) Pd(OAc)2 (0.1 equiv.), methyl acrylate (4 equiv.), PPh3 (0.3 equiv.), Et3N (1.5 equiv.), CH3CN, 90 °C, 12 h, 38%. DDQ, 2,3-Dichloro-5,6-dicyano-p-benzoquinone; DIPEA , N, N-Diisopropylethylamine; DMF, N,N-dimethylformamide; Et3N, triethylamine; NaBH4, sodium borohydrid; PCC, pyridinium chlorochromate; TBAF, Tetrabutylammonium fluoride trihydrate; TBSCl, tert-Butyl(chloro)dimethylsilane; TFA, Trifluoroacetic acid; THF, tetrahydrofuran.
