Fmoc: a more soluble analogue of the 9-fluorenylmethoxycarbonyl protecting group.
Fmoc: a more soluble analogue of the 9-fluorenylmethoxycarbonyl protecting group.
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Fmoc：9-芴基甲氧基羰基保护基的更易溶解的类似物。
DOI：
10.1021/jo9915832
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Nowick,JS
中科院分区：
文献类型：
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作者：
Stigers,KD;Koutroulis,MR;Chung,DM;Nowick,JS
材料和方法。除非另有说明，否则使用商业级试剂和溶剂而无需进一步纯化。按照 Grubbs 及其同事的描述，CH2Cl2 和 THF 在使用前通过无水 Al2O3 渗滤进行干燥。 10 芴从乙醇中重结晶。使用 1, 10-菲咯啉作为指示剂，甲苯作为溶剂，用 2-丁醇滴定正丁基锂。 11 对甲氧基苄胺在使用前进行蒸馏。所有反应均在氮气下进行；在弗里德尔-克来福特反应和光气化反应中，氮气管线通向鼓泡器，以防止 HCl 污染氮气歧管。除非另有说明，否则反应均以磁力搅拌。通过减压旋转蒸发除去溶剂。 2, 7-二叔丁基芴(2)。 3 向配备有氮气入口适配器、橡胶隔膜和机械搅拌器的冰冷却的 2 L 三颈圆底烧瓶中加入芴 (25.00 g, 150.4 mmol)、CS2 (100 mL) 和 FeCl3 (2.44 g, 15.0 mmol)。在5分钟内通过注射器添加2-氯-2-甲基丙烷(34.4mL，316mmol)。 10分钟后，除去冰浴，并将反应混合物搅拌3.5小时。然后加入水(100mL)，并将所得混合物在CH 2 Cl 2 (200mL)和1M HCl水溶液(100mL)之间分配。用另外的CH 2 Cl 2 (50mL)萃取水层，并连续用饱和NaHCO 3 水溶液(100mL)和饱和NaCl水溶液(75mL)洗涤合并的有机层，经MgSO 4 干燥，并浓缩，得到40.31g黄色固体。将残余物溶解在200mL己烷中，并借助额外的1L己烷将溶液通过硅胶柱(9cm h×8cm d)过滤。将滤液浓缩，得到38.82g(93％)的2，7-二叔丁基芴(2)，为白色固体，其无需进一步纯化即可用于下一步反应。分析样品从乙醇中重结晶：mp 120-122℃（lit.3 mp 122℃）； 1H NMR(500MHz，CDCl3)δ7.66(d，J)8.0Hz，2H)，7.56(s，2H)，7.38(d，J)8.1Hz，2H)，3.86(s，2H)，1.37(s，18H)； 13C NMR（500MHz，CDCl3）δ149.4、143.3、139.1、123.8、121.9、119.1、37.1、34.8、31.6。
Materials and Methods. Commercial-grade reagents and solvents were used without further purification except as indicated. CH2Cl2 and THF were dried prior to use by percolation through anhydrous Al2O3 as described by Grubbs and coworkers. 10 Fluorene was recrystallized from ethanol. n-Butyllithium was titrated with 2-butanol using 1, 10-phenanthroline as indicator and toluene as solvent. 11 p-Methoxybenzylamine was distilled prior to use. All reactions were performed under nitrogen; in the Friedel-Crafts and phosgenation reactions, the nitrogen line was vented to a bubbler to prevent contaminating the nitrogen manifold with HCl. Reactions were stirred magnetically, unless otherwise indicated. Solvents were removed by rotary evaporation under reduced pressure. 2, 7-Di-tert-butylfluorene (2). 3 An ice-cooled, 2-L, threenecked, round-bottomed flask equipped with a nitrogen inlet adapter, a rubber septum, and a mechanical stirrer was charged with fluorene (25.00 g, 150.4 mmol), CS2 (100 mL), and FeCl3 (2.44 g, 15.0 mmol). 2-Chloro-2-methylpropane (34.4 mL, 316 mmol) was added via syringe over 5 min. After 10 min, the ice bath was removed, and the reaction mixture was stirred for 3.5 h. Water (100 mL) was then added, and the resulting mixture was partitioned between CH2Cl2 (200 mL) and 1 M aqueous HCl (100 mL). The aqueous layer was extracted with additional CH2Cl2 (50 mL), and the combined organic layers were washed successively with saturated aqueous NaHCO3 (100 mL) and saturated aqueous NaCl (75 mL), dried over MgSO4, and concentrated to yield 40.31 g of a yellow solid. The residue was dissolved in 200 mL of hexanes, and the solution was filtered through a column of silica gel (9 cm h× 8 cm d) with the aid of an additional 1 L of hexanes. The filtrate was concentrated to yield 38.82 g (93%) of 2, 7-di-tert-butylfluorene (2) as a white solid, which was used in the next reaction without further purification. An analytical sample was recrystallized from ethanol: mp 120-122 C (lit. 3 mp 122 C); 1H NMR (500 MHz, CDCl3) δ 7.66 (d, J) 8.0 Hz, 2 H), 7.56 (s, 2 H), 7.38 (d, J) 8.1 Hz, 2 H), 3.86 (s, 2 H), 1.37 (s, 18 H); 13C NMR (500 MHz, CDCl3) δ 149.4, 143.3, 139.1, 123.8, 121.9, 119.1, 37.1, 34.8, 31.6.