Photoredox-Initiated α-Alkylation of Imines through a Three-Component Radical/Cationic Reaction
Photoredox-Initiated α-Alkylation of Imines through a Three-Component Radical/Cationic Reaction
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DOI：
10.1002/chem.201103062
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发表时间：
2012-01-01
影响因子：
4.3
通讯作者：
Masson, Geraldine
中科院分区：
文献类型：
--
作者：
Courant, Thibaut;Masson, Geraldine
亚胺的α烷基化是一种有价值的碳-碳键形成策略，尽管其α支化亚胺产品具有合成潜力，但它仍然是一个不发达的领域[1-3]。4由于竞争副反应，如Mannich缩合、N-烷基化和水解，亚胺与卤代烷的直接C-H键功能化已被证明是具有挑战性的。[1，5]基于烯胺[6]或烯胺[7]衍生物的分子间亲核烷基化反应的间接方法没有发现更有效。此外，报道的唯一相应的产物是α烷基化的羰基化合物。[8]据我们所知，目前还没有有效的方法来制备α烷基化亚胺。在这篇通讯中，我们揭示了一种新的亚胺的α烷基化反应，该反应可以通过光氧化还原介导的直接分子间C−H官能化来实现，涉及到自由基-阳离子多米诺骨牌过程。
The α-alkylation of imines is a valuable carbon-carbon bondforming strategy which is still an underdeveloped area, [1-3] despite the synthetic potential of its α-branched imine products. 4 The direct C-H bond functionalization of imines with alkyl halides has proven challenging due to competing side reactions, such as Mannich condensation, N-alkylation and hydrolysis. [1,5] The indirect approach based on the intermolecular nucleophilic alkylation reaction of enamine [6] or enamide [7] derivatives was not found more efficient. Moreover, the only corresponding products reported were α-alkylated carbonyl compounds. [8] To the best of our knowledge, there is no efficient method for the preparation of α-alkylated imines. In this communication, we disclose a novel αalkylation reaction of imines which can be achieved by photoredox-mediated direct intermolecular C−H functionalization of enamide derivatives, involving a radical-cationic domino process.