Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.
Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis.
复制标题
通过基于CO（II）的金属自由基催化，与原位生成的供体取代的重氮试剂对烷烃的不对称自由基环烷化。
DOI：
10.1021/jacs.6b11336
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发表时间：
2017-01-25
影响因子：
15
通讯作者：
Zhang XP
中科院分区：
文献类型：
--
作者：
Wang Y;Wen X;Cui X;Wojtas L;Zhang XP
给体取代的重氮试剂，原位产生的磺酰腙在碱的存在下，可以作为合适的自由基前体钴（II）为基础的金属自由基催化（MRC）。D2-对称手性卟啉钴配合物[Co（3，5-DitBu-Xu（2 '-Naph）Phyrin）]是一种有效的金属自由基催化剂，能够活化不同的N-芳基磺酰腙，用于广泛的烯烃的不对称自由基环丙烷化反应，以高产率提供相应的环丙烷，并有效控制非对映选择性和对映选择性。这种Co（II）为基础的金属自由基系统代表了第一个催化协议，可以有效地利用供体型重氮试剂的不对称烯烃环丙烷化。
Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradical catalysis (MRC). The cobalt(II) complex of D2-symmetric chiral porphyrin [Co(3,5-DitBu-Xu(2’-Naph)Phyrin)] is an efficient metalloradical catalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical cyclopropanation of a broad range of alkenes, affording the corresponding cyclopropanes in high yields with effective control of both diastereoselectivity and enantioselectivity. This Co(II)-based metalloradical system represents the first catalytic protocol that can effectively utilize donor-type diazo reagents for asymmetric olefin cyclopropanation.