Template-Assisted meta-C-H Alkylation and Alkenylation of Arenes
Template-Assisted meta-C-H Alkylation and Alkenylation of Arenes
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DOI：
10.1002/anie.201611360
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发表时间：
2017-03-13
影响因子：
16.6
通讯作者：
Maiti, Debabrata
中科院分区：
文献类型：
--
作者：
Bag, Sukdev;Jayarajan, Ramasamy;Maiti, Debabrata
为了扩大元功能化的范围，本文描述了一种基于嘧啶的模板，该模板可以利用烯丙醇，通过间羟基活化苄基磺酰基酯，有效地形成-芳基醛和酮。此外，烯丙基苯醚的原位烯烃和脱保护制备了a、b不饱和醛。在膦酸苄酯、苯乙基羰基和苯乙基磺酰基酯支架中也成功地实现了这些在芳烃位上的新功能化。这些成功的新功能化的关键是通过接受金属的电子云到能量较低的嘧啶环的p轨道上，创造了一个带电正电的钯中心，这有利于烯丙醇与金属中心的配位。
To expand the scope of meta-functionalization, a pyrimidine-based template effective for the formation of beta-aryl aldehydes and ketones, using allyl alcohols, by meta-C-H activation of benzylsulfonyl esters is described. In addition, a, b-unsaturated aldehydes were generated by in situ olefination and deprotection of allyl benzyl ethers. These new functionalizations at the meta-position of an arene have also been successfully implemented in benzylphosphonate, phenethyl carbonyl, and phenethylsulfonyl ester scaffolds. Key to these successful new functionalizations is the creation of an electropositive palladium center by accepting the electron cloud from the metal to the energetically low-lying p-orbitals of pyrimidine ring, and it favors coordination of allyl alcohol to the metal center.