Highly enantioselective Diels-Alder reaction of a photochemically generated o-quinodimethane with olefins
Highly enantioselective Diels-Alder reaction of a photochemically generated o-quinodimethane with olefins
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DOI：
10.1002/anie.200351567
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发表时间：
2003-01-01
影响因子：
16.6
通讯作者：
Bach, T
中科院分区：
文献类型：
--
作者：
Grosch, B;Orlebar, CN;Bach, T
高反应性邻醌二甲烷可以通过从光化学激发的邻烷基取代的苯甲醛A分子内H-提取来产生（方案1）。它在低温下与烯烃的反应代表了二烯和亲二烯体之间经典的Diels-Alder反应的光化学替代。[1]光化学反应是由Yang和里瓦斯在1961年发现的[2]，此后得到了深入的研究。结果表明，（Z）-B和（E）-B中只有E非对映异构体（t> 1 s）参与环加成反应，而Z非对映异构体发生快速互变异构（t= 30 ns-1 μs）. [3，4]由于这种选择性，
A highly reactive ortho-quinodimethane can be generated by intramolecular H-abstraction from a photochemically excited ortho-alkyl-substituted benzaldehyde A (Scheme 1). Its reaction with alkenes at low temperature represents a photochemical alternative to the classical Diels–Alder reaction between a diene and a dienophile.[1] The photochemical reaction was dicovered by Yang and Rivas in 1961 [2] and was studied intensively thereafter. It was shown that only the E diastereoisomer (t> 1 s) of the two formed enols (Z)-B and (E)-B enters the cycloaddition reaction, while the Z diastereoisomer is subject to fast (t= 30 ns–1 μs) tautomerization.[3, 4] As a consequence of this selectivity and due to the