Enantio- and Regioselective Intermolecular Benzylic and Allylic C-H Bond Amination
Enantio- and Regioselective Intermolecular Benzylic and Allylic C-H Bond Amination
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DOI：
10.1002/anie.201208906
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发表时间：
2013-01-01
影响因子：
16.6
通讯作者：
Katsuki, Tsutomu
中科院分区：
文献类型：
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作者：
Nishioka, Yota;Uchida, Tatsuya;Katsuki, Tsutomu
CN键存在于各种天然产物的骨架中，其立体选择性形成是有机合成中的一个重要目标。由于过渡金属配合物的不对称氮烯转移催化作用[1]，在立体选择性C3 N键形成方面取得了显着的进展，并且已经报道了许多高对映选择性的方法。[2-4]然而，这些反应使用低原子效率的氮烯前体，如N-甲苯磺酰亚氨基苯基碘烷或原位制备的等价物。因此，使用原子有效的叠氮化合物，特别是携带容易去除的N-保护基团的叠氮化合物作为氮烯前体的CCH 3 H胺化引起了越来越多的兴趣。[5]尽管最近已经报道了使用叠氮化物进行C3 H4胺化的有效方法，但它们不是对映选择性的，[6-8]并且使用叠氮化物进行C3 H4胺化中的对映体控制仍然是一个巨大的挑战。我们最近发现，使用铱-salen配合物1作为催化剂，可以以高对映选择性实现分子内苄基C1 H1 H2胺化，[9]并进一步探索了在室温下C1 H2与配合物1的分子间胺化。然而，茚满的胺化缓慢并且对映选择性差（方案1）。
CÀN bonds appear in the frameworks of various natural products, and their stereoselective formation is an important objective in organic synthesis. With the benefit of asymmetric nitrene-transfer catalysis by transition metal complexes,[1] remarkable advancements have been made in stereoselective CÀN bond formation, and many highly enantioselective methods have been reported.[2–4] However, these reactions use low-atom-efficient nitrene precursors such as N-tosyliminophenyliodinane or in situ prepared equivalents. Thus, CÀH amination using atom-efficient azides, especially ones bearing a readily removable N-protecting group, as nitrene precursors have attracted a growing interest.[5] Although efficient methods for CÀH amination using azides have been recently reported, they are not enantioselective,[6–8] and enantiocontrol in CÀH amination using an azide is still a great challenge. We recently found that intramolecular benzylic CÀH amination could be implemented with high enantioselectivity using iridium–salen complex 1 as the catalyst,[9] and further explored an intermolecular version of CÀH amination with complex 1 at room temperature. However, the amination of indane was slow and the enantioselectivity was poor (Scheme 1).