Toward a protecting-group-free halogen-metal exchange reaction: practical, chemoselective metalation of functionalized aromatic halides using dianion-type zincate, tBu4ZnLi2.
Toward a protecting-group-free halogen-metal exchange reaction: practical, chemoselective metalation of functionalized aromatic halides using dianion-type zincate, tBu4ZnLi2.
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DOI：
10.1021/ja058246x
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发表时间：
2006-06
影响因子：
15
通讯作者：
M. Uchiyama;Taniyuki Furuyama;Minoru Kobayashi;Yotaro Matsumoto;Kentaro Tanaka
中科院分区：
文献类型：
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作者：
M. Uchiyama;Taniyuki Furuyama;Minoru Kobayashi;Yotaro Matsumoto;Kentaro Tanaka
采用四叔丁基锌酸二锂（tBu 4 ZnLi 2）通过卤素-锌交换反应制备了芳香族锌酸盐化合物。该试剂允许高效制备高度官能化的芳族锌酸盐，特别是具有亲电官能团如酯、酰胺、醇和酚的那些。卤素-锌交换反应，然后亲电捕获（与烯丙基溴或苯甲醛）被证明是一个强大的工具，C-C键形成功能化的芳环。该功能化的芳香族锌酸盐中间体也被发现进行铜和钯催化的C-C键形成反应，具有良好的产率和高的化学选择性。
A versatile preparation method for aromatic zincate compounds through a halogen-zinc exchange reaction using dilithium tetra-tert-butylzincate (tBu4ZnLi2) has been developed. This reagent permits efficient preparation of highly functionalized aromatic zincates, particularly, those with electrophilic functional groups, such as ester, amide, alcohol, and phenol. Halogen-zinc exchange reactions followed by electrophilic trapping (with allyl bromide or benzaldehyde) proved to be a powerful tool for C-C bond formation on functionalized aromatic rings. The functionalized aromatic zincate intermediate was also found to undergo copper- and palladium-catalyzed C-C bond-forming reactions with good yields and high chemoselectivity.