Asymmetric Nucleophilic Catalysis with an Octahedral Chiral-at-Metal Iridium(III) Complex
Asymmetric Nucleophilic Catalysis with an Octahedral Chiral-at-Metal Iridium(III) Complex
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DOI：
10.1021/acscatal.7b01296
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发表时间：
2017-08-01
期刊：
影响因子：
12.9
通讯作者：
Meggers, Eric
中科院分区：
文献类型：
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作者：
Cruchter, Thomas;Medvedev, Michael G.;Meggers, Eric
在此，我们报道了一个亲核八面体手性金属铱（III）配合物的设计、合成和应用。我们证明，该络合物的对映体纯形式作为一个有效的催化剂的不对称Steglich重排的O-酰化azlactones（高达96%ee和99%的收率）和相关的不对称黑色重排的O-酰化苯并呋喃酮（高达94%ee和99%的收率）。我们提供洞察这两个酰基迁移反应的机制和催化剂的手性识别与活性催化剂和催化中间体类似物的晶体结构的方式，以及基于它们的量子化学计算。此外，我们证明，所提出的催化剂也有效地催化芳基烷基烯酮和2-氰基吡咯之间的不对称反应，得到相应的α-手性N-酰基吡咯（高达95%ee和99%产率）。
Herein, we report about the design, synthesis, and application of a nucleophilic octahedral chiral-only-at metal iridium(III) complex. We demonstrate that the enantiopure form of this complex serves as an efficient catalyst for the asymmetric Steglich rearrangement of O-acylated azlactones (up to 96% ee and 99% yield) and the related asymmetric Black rearrangement of O-acylated benzofuranones (up to 94% ee and 99% yield). We provide insight into the mechanisms of these two acyl migration reactions and the catalyst's manner of chiral recognition with crystal structures of the active catalyst and a catalysis intermediate analog, as well as with quantum chemical calculations based on them. Furthermore, we demonstrate that the presented catalyst also efficiently catalyzes the asymmetric reaction between aryl alkyl ketenes and 2-cyanopyrrole to give the corresponding alpha-chiral N-acyl pyrroles (up to 95% ee and 99% yield).