氨基的保护及脱保护 下载本文

2. H. Kunz, C. Unverzagt., Angew. Chem. Int. Ed. Engl., 1984, 23, 436 3. O. Dangles, F. Guibe et al., J. Org. Chem., 1987, 52, 4984; P. Four, F. Guibe.,

Tetrahedron Lett., 1982, 23, 1825

4. S. Lemaire-Audoire, M. Savignac et al., Tetrahedron Lett., 1994, 35, 8783; E. Blart, J. M. Bernard et al., Tetrahedron Lett., 1997, 38, 2955; J. P. Genet, E. Blart et al., Tetrahedron Lett., 1993, 34, 4189 5. Y. Kanda, H. Arai et al., J. Med. Chem., 1992, 35, 2781

6. J. Lee, J. H. Griffin, T. I. Nicas., J. Org. Chem., 1996, , 3983

612.4.2.1 Pd(PPh3)4-THF体系脱除烯丙氧羰基(Alloc)示例

Y. Matsushima; H. Itoh etal., J. Chem. Soc. Perkin Trans. 1., 2004, 7, 949 To a solution of the Alloc protected ester (140.7 mg, 0.2.23 mmol) and 1,3-dimethylbarbituric acid (228 mg, 1.46 mmol) in THF (15 mL) was added tetrakis(triphenylphosphine)palladium (43.9 mg, 0.0379 mmol, 17 mol%), and the resulting mixture was stirred at rt for 27 h. The mixture was then poured into saturated aq. NaHCO3 and extracted four times with Et2O. The combined extract was dried (MgSO4) and concentrated in vacuo. The residue was purified by chromatography (CHCl3/MeOH, 20 : 1 to 2 : 1) to give the corresponding free amino ester as a colorless oil (79.5 mg, 65%).

2.4.2.2 Pd(PPh3)4/Me2NTMS体系脱除烯丙氧羰基(Alloc)示例

P. Angehrm; S. Buchmann et al., J. Med. Chem., 1992, 47(6), 1487 To a solution of 112 (0.97 g, 1.4 mmol) in CH2Cl2 (19 mL) were added dimethylamino- trimethylsilane (1.32 mL, 8.4 mol) and trimethylsilyl trifluoroacetate (1.45 mL, 8.4 mmol). The solution was stirred at 20 °C for 10 min, and then Pd(PPh3)4 (97 mg, 0.084 mmol) was added and stirring was continued for 2.5 h. The mixture was evaporated and the residual oil was dissolved in EtOAc (50 mL). The solution was washed with 10% aq NaHCO3 and brine, dried, and evaporated. The residue was chromatographed (SiO2; EtOAc/hexane 1:2) to give 113 (0.67 g, 78%): foam; TLC

Rf ) 0.27 (EtOAc).

2.5 三甲基硅乙氧羰基(Teoc)

三甲基硅乙氧羰基(Teoc)同前面提到的Cbz、Boc, Fmoc 和Alloc不同,它对酸、大部分碱,及贵金属催化等都很稳定,在它的存在下,Cbz、Boc,Fmoc和Alloc等可选择性去保护,而它的脱去则通常在氟负离子进行。如TBAF[1]、TEAF和HF[2]等。另外,TFA也可选择性去保护三甲基硅乙氧羰基[3]。

1. Seth, Punit P; Ray, Robinson, Dale E et al Bioorg. Med. Chem. Lett., 2004, 14(22), 5569-5572; Olsen, Christian A; Joergensen, Malene R et al Eur. J. Org. Chem., 2003, 17, 3288-3299; Boger, Dale L; Kim, Seong Heon et al J. Am. Chem. Soc., 2001, 123(9), 1862-1871

2. Tius, Marcus A; Thurkauf, Andrew; Tetrahedron Lett., 1986, 27(38), 4541-4544 3. Park, Haengsoon; Cao, Bin et al J. Org. Chem., 2001, 66(21), 7223-7226 2.5.1三甲基硅乙氧羰基(Teoc)的引入

Teoc-Cl[1, 2]、Teoc-OSu[2]或Teoc-OBt[3]在有机溶剂,碱的存在下同氨基化合物反应则可得到Teoc保护的氨基衍生物。

1. Zubert, Sheena; Glen, Angela et al Tetrahedron Lett. 1998, 39(41), 7567-7570; Trost, Barry M; Cossy, Janine; J. Am. Chem. Soc., 1982, 104(24), 6881-6882; Sulline, David W; Bobik, Thomas A et al J. Am. Chem. Soc., 1993, 115(15), 6646-6651

2. Shute, Richard; Rich, Daniel H; Synthesis, 1987, 4, 346-349

3. Boger, Dale L; Kim, Seng Heon et al., J. Am. Chem. Soc., 2001, 123(9),

1862-1871; Boger, Dale L; Kim, Seng Heon et al., J. Am. Chem. Soc., 2000, 122(30), 7416-7417

2.5.1.1 Teoc-Cl引入三甲基硅乙氧羰基(Teoc)示例

Shute, Richard; Rich, Daniel H; Synthesis, 1987, 4, 346-349

NaHCO3(3.78 g, 45 mmol) and compound 1(15 mmol) are added to water (15 ml) and the mixture is stirred at room temperature for 30 min or until the majority of the solids dissolve. To this suspension is added a solution of Teoc-Cl in dioxane (30 ml). The resultant mixture is stirred vigorously at room temperature overnight, poured into water (50 ml) and extracted with ether (3 x 50 ml), the organic extracts being discarded. The aqueous layer is acidified to Ph = 2 with saturated potassium hydrogen sulfate solution and extracted with ether (3 x 50 ml). The combined organic extracts are washed with water (3 x 75 ml), dried with MgSO4, and evaporated to give compound 2 (). 2.5.1.2 Teoc-OSu引入三甲基硅乙氧羰基(Teoc)示例1

Shute, Richard; Rich, Daniel H; Synthesis, 1987, 4, 346-349

To a stirred suspension of compound 1 (0.13 g, 1 mmol) in water (1 ml) is added a solution of triethylamine (0.26 g, 2.6 mmol) in dioxane (1 ml). To the resultant solution is added solid Teoc-OSu (0.29 g, 1.1 mmol). The mixture is stirred at room temperature overnight, then diluted with water (5 ml), acidified with saturated potassium hydrogen sulfate solution, and extracted with ether (3 x 15 ml). The combined organic layers are washed with water (4 x 20 ml), dried with MgSO4, and evaporated to afford compound 2 (0.23 g, 84%) as an oily residue.

Teoc-OSu引入三甲基硅乙氧羰基(Teoc)示例2

Shute, Richard; Rich, Daniel H; Synthesis, 1987, 4, 346-349

To a stirred suspension of compound 1 (0.13 g, 1 mmol) in water (1 ml) is added a solution of triethylamine (0.26 g, 2.6 mmol) in dioxane (1 ml). To the resultant solution is added solid Teoc-OSu (0.29 g, 1.1 mmol). The mixture is stirred at room temperature overnight, then diluted with water (5 ml), acidified with saturated potassium hydrogen sulfate solution, and extracted with ether (3 x 15 ml). The combined organic layers are washed with water (4 x 20 ml),