tert-butylsulfonyl (Bus), a new protecting group for amines
tert-butylsulfonyl (Bus), a new protecting group for amines
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DOI：
10.1021/jo971455i
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发表时间：
1997-11-28
影响因子：
3.6
通讯作者：
Shang, MY
中科院分区：
文献类型：
--
作者：
Sun, P;Weinreb, SM;Shang, MY
磺酰基在保护胺和其他含氮官能团方面具有悠久的历史。1磺酰胺最吸引人的特征之一，它们对各种反应条件的稳定性，通常已被证明是一种责任，因为在高度官能化的敏感底物中，去除通常是有问题的。近年来，N-磺酰基保护基团的库已经通过添加适合温和去除的新品种而得到改进。2-4在一些正在进行的项目中，我们需要能够承受强金属化条件的磺酰胺保护基，并且还需要容易裂解的磺酰胺保护基。由于几乎所有已知的体系，包括大多数芳基磺酰基，都带有酸性质子，因此很明显有必要开发一种新型的磺酰胺。在本说明中，我们描述了叔丁基磺酰基（Bus）用于保护伯胺和仲胺的效用。毫无疑问，胺的叔丁基磺酰基保护以前没有使用过，因为叔丁基磺酰氯非常不稳定，而且通常不会在硫处用胺进行亲核置换。然而，里奇和法卡斯发现，容易制备的叔丁基亚磺酰氯（1）与二乙胺反应得到相应的亚磺酰胺（2，R1）R2）Et），其可以用高锰酸钾氧化成叔丁基磺酰胺（3，R1）R2
Sulfonyl groups have had a long history in protection of amines and other nitrogeneous functionality. 1 One of the most attractive features of sulfonamides, their stability to a wide array of reaction conditions, has commonly proven a liability, since removal is oftentimes problematic in highly functionalized, sensitive substrates. In recent years the arsenal of N-sulfonyl protecting groups has been improved by addition of new varieties amenable to mild removal. 2-4 In connection with some ongoing projects, we required a sulfonamide protecting group capable of withstanding strong metalation conditions and also one easily cleaved. Since virtually all known systems, including most arylsulfonyl groups, bear acidic protons, it became evident that development of a new type of sulfonamide was necessary. In this note we describe the utility of the tert-butylsulfonyl group (Bus) for protection of primary and secondary amines. Undoubtedly tert-butylsulfonyl protection of amines has not previously been used since tert-butylsulfonyl chloride is quite unstable and furthermore does not normally undergo nucleophilic displacement at sulfur with amines. 5 Richey and Farkas have found, however, that readily prepared tert-butylsulfinyl chloride (1) reacts with diethylamine to give the corresponding sulfinamide (2, R1) R2) Et), which could be oxidized with potassium permanganate to the tert-butylsulfonamide (3, R1) R2