Nickel-catalyzed coupling reactions of alkyl electrophiles, including unactivated tertiary halides, to generate carbon-boron bonds.
Nickel-catalyzed coupling reactions of alkyl electrophiles, including unactivated tertiary halides, to generate carbon-boron bonds.
复制标题
DOI：
10.1021/ja304068t
复制
发表时间：
2012-06-27
影响因子：
15
通讯作者：
Fu, Gregory C.
中科院分区：
文献类型：
--
作者：
Dudnik, Alexander S.;Fu, Gregory C.
通过使用由 NiBr2·二甘醇二甲醚和 pybox 配体（两者均可商购）原位形成的催化剂，我们实现了未活化叔烷基亲电子试剂偶联反应的第一个例子，以及我们首次成功地产生了除 C-C 键之外的键的镍催化偶联。具体来说，我们已经确定该催化剂可在温和条件下用二硼试剂完成未活化的叔卤代、仲卤代烷和伯卤代烷的宫浦型硼基化，以提供烷基硼酸酯，这是一类具有实质性（和扩展性）效用的化合物。事实上，叔烷基溴的umpolung硼基化可以在低至-10°C的温度下实现。该方法表现出良好的官能团相容性并且具有区域特异性，这两者都是传统的烷基硼酸酯合成方法所存在的问题。与看似相关的镍催化 C-C 键形成过程相比，在这种镍催化 C-B 键形成反应中，叔卤化物比仲卤化物或伯卤化物更具反应性；鉴于这两种转变都可能遵循氧化加成的内球电子转移途径，这种分歧尤其值得注意。
Through the use of a catalyst formed in situ from NiBr2•diglyme and a pybox ligand (both of which are commercially available), we have achieved our first examples of coupling reactions of unactivated tertiary alkyl electrophiles, as well as our first success with nickel-catalyzed couplings that generate bonds other than C–C bonds. Specifically, we have determined that this catalyst accomplishes Miyaura-type borylations of unactivated tertiary, secondary, and primary alkyl halides with diboron reagents to furnish alkylboronates, a family of compounds with substantial (and expanding) utility, under mild conditions; indeed, the umpolung borylation of a tertiary alkyl bromide can be achieved at a temperature as low as −10 °C. The method exhibits good functional-group compatibility and is regiospecific, both of which can be issues with traditional approaches to the synthesis of alkylboronates. In contrast to seemingly related nickel-catalyzed C–C bond-forming processes, tertiary halides are more reactive than secondary or primary halides in this nickel-catalyzed C–B bond-forming reaction; this divergence is particularly noteworthy in view of the likelihood that both transformations follow an inner-sphere electron-transfer pathway for oxidative addition.
登录
查看更多内容
镍催化带有氧离去基团的外消旋二级亲电子试剂的对映选择性交叉偶联。
影响因子：
15
作者：
Oelke, Alexander J.;Sun, Jianwei;Fu, Gregory C.
通讯作者：
Fu, Gregory C.
影响因子：
15
作者：
O'Brien, Jeannette M.;Lee, Kang-sang;Hoveyda, Amir H.
通讯作者：
Hoveyda, Amir H.
影响因子：
8.4
作者：
Hu, Xile
通讯作者：
Hu, Xile
影响因子：
15
作者：
Lu, Zhe;Wilsily, Ashraf;Fu, Gregory C.
通讯作者：
Fu, Gregory C.
影响因子：
15
作者：
Guzman-Martinez, Aikomari;Hoveyda, Amir H.
通讯作者：
Hoveyda, Amir H.