Regio- and Stereospecific C- and O-Allylation of` Phenols via π-Allyl Pd Complexes Derived from Allylic Ester Carbonates
Regio- and Stereospecific C- and O-Allylation of` Phenols via π-Allyl Pd Complexes Derived from Allylic Ester Carbonates
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DOI：
10.1021/acs.joc.6b02608
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发表时间：
2017-01-20
影响因子：
3.6
通讯作者：
Deardorff, Donald R.
中科院分区：
文献类型：
--
作者：
Discolo, Christopher A.;Graves, Alexander G.;Deardorff, Donald R.
两个互补的策略已经开发了通过一个共同的π-烯丙基钯络合物的酚的C-和O-烯丙基化。虽然通过这种方法的酚的O-烯丙基化是一个公认的反应的通用性，相关的对位选择性C-烯丙基化反应仍处于起步阶段。由烯丙基碳酸酯和钯（0）催化剂生成的阳离子π-烯丙基钯中间体与9种不同的苯酚发生了Friedel-Crafts型顺选择性C-烯丙基化反应。C-和O-烯丙基化的产品得到良好的到优异的产率以下金属催化的区域和立体有择取代的1，3-转座。还确定了控制获得烯丙基化产物的条件。最后，两个烯丙基化产物之间建立的平衡的研究表明，O-烯丙基化的化合物是动力学产物和C-烯丙基化的化合物的热力学产物。
Two complementary strategies have been developed for the C- and O-allylation of phenols via a common pi-allyl Pd complex. While O-allylation of phenols by this method is a well recognized reaction of general utility, the associated para-selective C-allylation reaction is still in its infancy. Cationic pi-allyl Pd intermediates, derived from allylic ester carbonates and palladium(0) catalyst, were found to undergo the Friedel-Crafts-type paraselective C-allylations with nine different phenols. Both C- and O-allylated products were obtained in good to excellent yields following a metal-catalyzed regio- and stereospecific substitutive 1,3-transposition. Conditions were also identified that control access to either allylated product. Finally, a study of the equilibrium established between the two allylation products revealed that the O-allylated compound was the kinetic product and the C-allylated compound the thermodynamic product.