Diastereoselective Carbometalation of Oxa- and Azabicyclic Alkenes under Iron Catalysis
Diastereoselective Carbometalation of Oxa- and Azabicyclic Alkenes under Iron Catalysis
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DOI：
10.1002/anie.201006180
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发表时间：
2011-01-01
影响因子：
16.6
通讯作者：
Nakamura, Masaharu
中科院分区：
文献类型：
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作者：
Ito, Shingo;Itoh, Takuma;Nakamura, Masaharu
过渡金属催化的烯烃碳金属化是选择性形成碳-碳键的强大合成工具。通过连续亲电捕获中间有机金属物质，可以在单锅程序中实现连续 sp3 碳中心的区域和立体选择性构建。 [1]尽管铁催化剂因其经济和环境效益而受到越来越多的关注，[2]它们在立体选择性碳金属化（随后是亲电捕获）中的应用仅限于炔烃[3]和环丙烯[4]底物。[5]在此，我们报道了使用新开发的邻亚苯基二膦配体，用芳基锌试剂对氧杂和氮杂双环烯烃进行高度非对映选择性铁催化的碳金属化（方案1）；这些配体被发现可以抑制 β-杂原子消除途径并实现连续的亲电子捕获（方案 2，路径 a 与路径 b）。[6–8]
The transition-metal-catalyzed carbometalation of alkenes is a powerful synthetic tool for the selective formation of carbon–carbon bonds. Through sequential electrophilic trapping of the intermediate organometallic species, regio-and stereoselective construction of contiguous sp3 carbon centers can be achieved in a single-pot procedure.[1] Although iron catalysts are attracting increased attention because of their economical and environmental benefits,[2] their application in stereoselective carbometalation (followed by electrophilic trapping) has been limited to only alkyne [3] and cyclopropene [4] substrates.[5] Herein, we report a highly diastereoselective iron-catalyzed carbometalation of oxa-and azabicyclic alkenes with arylzinc reagents using the newly developed ortho-phenylene diphosphine ligands (Scheme 1); these ligands were found to suppress the β-heteroatom elimination pathway and enable sequential electrophilic trapping (Scheme 2, path a versus path b).[6–8]