Highly Enantioselective Intramolecular Cyanoamidation: (+)-Horsfiline, (-)-Coerulescine, and (-)-Esermethole (Retracted Article)
Highly Enantioselective Intramolecular Cyanoamidation: (+)-Horsfiline, (-)-Coerulescine, and (-)-Esermethole (Retracted Article)
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DOI：
10.1021/ol902949d
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发表时间：
2010-03-05
期刊：
影响因子：
5.2
通讯作者：
Douglas, Christopher J.
中科院分区：
文献类型：
--
作者：
Reddy, Venkata Jaganmohan;Douglas, Christopher J.
报道了首个具有对映选择性（ee达99%）的合成3,3-二取代吲哚的不对称氰酰胺化反应。具有手性磷酰胺配体的钯催化剂激活氰甲酰胺C-CN键，该键随后被系链烯烃功能化，得到全碳季立体中心。使用八氢单磷的N，N-(i-Pr)(2)衍生物可以生产具有高对体选择性的氧吲哚，现在可以耐受含游离N- h基团的氰甲酰胺，可能实现无保护基团的合成。氰胺化的氧吲哚产物可迅速转化为(+)-马丝氨酸、(-)-蓝胺和(-)-esermethole。
The first asymmetric cyanoamidation with synthetically useful enantioselectivity (ee up to 99%) to produce 3,3-disubstituted oxindoles is reported. Palladium catalysts with chiral phosphoramidite ligands activate the cyanoformamide C-CN bond, which is subsequently functionalized with a tethered alkene to give all-carbon quaternary stereocenters. The use of the N,N-(i-Pr)(2) derivative of octahydro-MonoPhos allowed the production of oxindoles with high enantioselectivities, Cyanoformamides bearing free N-H groups are now tolerated, potentially allowing protecting-group-free synthesis. Oxindole products of cyanoamidation are rapidly transformed into (+)-horsfiline, (-)-coerulescine, and (-)-esermethole.