Regioselective unsymmetrical tetraallylation of C(60) through palladium catalysis.
Regioselective unsymmetrical tetraallylation of C(60) through palladium catalysis.
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DOI：
10.1021/ja9071173
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发表时间：
2009-10
影响因子：
15
通讯作者：
Masakazu Nambo;A. Wakamiya;S. Yamaguchi;K. Itami
中科院分区：
文献类型：
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作者：
Masakazu Nambo;A. Wakamiya;S. Yamaguchi;K. Itami
钯催化的C（60）的四烯丙基化反应，选择性地发生与不对称加成模式已被建立。在1，2-Cl（2）C（6）H（4）中，用CH（2）= CHCH（2）Cl、CH（2）=CHCH（2）SnBu（3）和PdCl（2）[P（OPh）（3）]（2）在50 ℃下处理C（60），以74%的产率和几乎完全的区域选择性得到四烯丙基化富勒烯。机理研究表明，（i）四烯丙基化通过连续的亲核/亲电烯丙基化进行[可能通过双（π-烯丙基）钯中间体]和（ii）空间（对于第一个二烯丙基化）和电子（对于第二个二烯丙基化）因素是负责高区域选择性。
A Pd-catalyzed tetraallylation of C(60) that selectively occurs with an unsymmetrical addition pattern has been established. Treatment of C(60) with CH(2)=CHCH(2)Cl, CH(2)=CHCH(2)SnBu(3), and PdCl(2)[P(OPh)(3)](2) in 1,2-Cl(2)C(6)H(4) at 50 degrees C afforded the tetraallylated fullerene in 74% yield with virtually complete regioselectivity. Mechanistic investigations showed that (i) tetraallylation proceeds through consecutive nucleophilic/electrophilic allylations [likely via a bis(pi-allyl)palladium intermediate] and (ii) both steric (for the first diallylation) and electronic (for the second diallylation) factors are responsible for the high regioselectivity.