Replacing conventional carbon nucleophiles with electrophiles: nickel-catalyzed reductive alkylation of aryl bromides and chlorides.
Replacing conventional carbon nucleophiles with electrophiles: nickel-catalyzed reductive alkylation of aryl bromides and chlorides.
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DOI：
10.1021/ja301769r
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发表时间：
2012-04-11
影响因子：
15
通讯作者：
Weix, Daniel J.
中科院分区：
文献类型：
--
作者：
Everson, Daniel A.;Jones, Brittany A.;Weix, Daniel J.
介绍了一种通过两个亲电碳的化学选择性结合合成烷基芳烃的一般方法。在优化的条件下，多种芳基和乙烯基溴与烷基溴的还原偶联以高产率进行。在类似的条件下，活化的芳基氯也可以与溴代烷烃偶联。该方案具有高度的官能团耐受性（−OH、−NHTs、−OAc、− OTs、− OTf、−COMe、−NHBoc、−NHCbz、−CN、− SO2 Me），并且反应在工作台上组装，没有特殊的预防措施来排除空气或水分。该反应显示出与传统的交叉偶联反应不同的化学选择性，例如Suzuki-Miyaura，Stille和Hiyama-Denmark反应。对于有机硼（−Bpin）、有机锡（− SnMe 3）和含有机卤化物（X-R-[M]）的有机硅（− SiMe 2 OH），同时具有亲电和亲核碳的底物导致亲电碳（R-X）处的选择性偶联，和亲核碳（R-[M]）处没有反应。Hammett的研究表明，σ和σ（−）参数与取代芳基溴与溴代烷烃反应的相对速率呈线性相关。这些相关性的小ρ值（1.2-1.7）表明溴代芳烃的氧化加成不是转换频率决定步骤。反应速率与烷基溴和催化剂的浓度成正相关，与锌（还原剂）的量无关，与芳基卤的浓度成负相关。这些结果和研究与有机还原剂（TDAE）反对有机锌试剂的中间体。
A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH, −NHTs, −OAc, −OTs, −OTf, −COMe, −NHBoc, −NHCbz, −CN, −SO2Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki–Miyaura, Stille, and Hiyama–Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R–X) and no reaction at the nucleophilic carbon (R–[M]) for organoboron (−Bpin), organotin (−SnMe3), and organosilicon (−SiMe2OH) containing organic halides (X–R–[M]). A Hammett study showed a linear correlation of σ and σ(−) parameters with the relative rate of reaction of substituted aryl bromides with bromoalkanes. The small ρ values for these correlations (1.2–1.7) indicate that oxidative addition of the bromoarene is not the turnover-frequency determining step. The rate of reaction has a positive dependence on the concentration of alkyl bromide and catalyst, no dependence upon the amount of zinc (reducing agent), and an inverse dependence upon aryl halide concentration. These results and studies with an organic reductant (TDAE) argue against the intermediacy of organozinc reagents.
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影响因子：
3.6
作者：
COLON, I;KELSEY, DR
通讯作者：
KELSEY, DR
影响因子：
2.8
作者：
AMATORE, C;PFLUGER, F
通讯作者：
PFLUGER, F
“水上的苯并卤化物”与芳基卤化物之间的跨偶联：二丁香乙烷的合成。
DOI：
10.1039/b922280d
发表时间：
2010-01-28
期刊：
Chemical communications (Cambridge, England)
影响因子：
--
作者：
Duplais C;Krasovskiy A;Wattenberg A;Lipshutz BH
通讯作者：
Lipshutz BH
影响因子：
1.8
作者：
BROWN, HC;BHAT, NG;SREBNIK, M
通讯作者：
SREBNIK, M
影响因子：
2.8
作者：
BROWN, HC;COLE, TE
通讯作者：
COLE, TE