Dehalogenative Deuteration of Unactivated Alkyl Halides Using D<sub>2</sub>O as the Deuterium Source
作者:Aiyou Xia、Xin Xie、Xiaoping Hu、Wei Xu、Yuanhong Liu
DOI:10.1021/acs.joc.9b02026
日期:2019.11.1
The general dehalogenation of alkyl halides with zinc using D2O or H2O as a deuterium or hydrogen donor has been developed. The method provides an efficient and economic protocol for deuterium-labeled derivatives with a wide substrate scope under mild reaction conditions. Mechanistic studies indicated that a radical process is involved for the formation of organozinc intermediates. The facile hydrolysis
<i>N</i>-Acyl Amino Acid Ligands for Ruthenium(II)-Catalyzed <i>meta</i>-C–H <i>tert</i>-Alkylation with Removable Auxiliaries
作者:Jie Li、Svenja Warratz、Daniel Zell、Suman De Sarkar、Eloisa Eriko Ishikawa、Lutz Ackermann
DOI:10.1021/jacs.5b08435
日期:2015.11.4
Acylated amino acid ligands enabled ruthenium(II)-catalyzed C-H functionalizations with excellent levels of meta-selectivity. The outstanding catalytic activity of the ruthenium(II) complexes derived from monoprotected amino acids (MPAA) set the stage for the first ruthenium-catalyzed meta-functionalizations with removable directing groups. Thereby, meta-alkylated anilines could be accessed, which
酰化氨基酸配体使钌 (II) 催化的 CH 官能化具有出色的元选择性。源自单保护氨基酸 (MPAA) 的钌 (II) 配合物的出色催化活性为第一个具有可移除导向基团的钌催化元功能化奠定了基础。因此,可以使用间烷基化苯胺,这是很难通过其他直接苯胺官能化方法制备的。多功能钌 (II)-MPAA 的稳健性通过在苯胺衍生物以及吡啶基、嘧啶基和吡唑基取代的芳烃上用叔烷基卤化物进行远程 CH 转化具有挑战性来体现。详细的机理研究为最初的可逆 CH 钌化提供了强有力的支持,然后通过均裂键裂解激活 SET 型 C-Hal。动力学分析通过反应速率对钌催化剂浓度的不寻常的二阶依赖性证实了这一假设。总体而言,该报告强调了源自酰化氨基酸的钌配合物的卓越催化活性,这应该证明有助于超越远程功能化的 CH 活化化学。
Nickel-catalyzed alkyl–alkyl cross-coupling reactions of non-activated secondary alkyl bromides with aldehydes as alkyl carbanion equivalents
作者:Chenghao Zhu、Junliang Zhang
DOI:10.1039/c9cc00307j
日期:——
A novel nickel-catalyzed alkyl–alkyl cross coupling of non-activatedsecondaryalkylbromides with aldehydes via hydrazone intermediates has been developed. Aldehydes as alkyl carbanion equivalents replace traditional organometallic reagents. This coupling occurs on the carbon of the hydrazone rather than the nitrogen. In addition, non-activated primary and tertiary alkylbromides also undergo the
Nickel-catalyzed cross-coupling of unactivated tertiary alkyl electrophiles with alkylmetal reagents is still a challenge. We report herein a nickel-catalyzed Negishi cross-coupling of alkyl halides, including unactivated tertiary halides, with boron-stabilized organozinc reagent BpinCH2ZnI, yielding versatile organoboron products with high functional-group tolerance. Importantly, the Bpin group was