Silicon–Carbon Bond Formation via Nickel-Catalyzed Cross-Coupling of Silicon Nucleophiles with Unactivated Secondary and Tertiary Alkyl Electrophiles
作者:Crystal K. Chu、Yufan Liang、Gregory C. Fu
DOI:10.1021/jacs.6b03465
日期:2016.5.25
cross-coupling methods for the formation of C-C bonds from unactivated alkyl electrophiles have been described in recent years. In contrast, progress in the development of methods for the construction of C-heteroatom bonds has lagged; for example, there have been no reports of metal-catalyzed cross-couplings of unactivated secondary or tertiaryalkyl halides with silicon nucleophiles to form C-Si bonds. In this
近年来,已经描述了用于从未活化的烷基亲电试剂形成 CC 键的一系列交叉偶联方法。相比之下,C-杂原子键构建方法的开发进展滞后;例如,没有关于未活化的仲或叔烷基卤化物与硅亲核试剂在金属催化下交叉偶联形成 C-Si 键的报道。在这项研究中,我们解决了这一挑战,确定了一种简单的市售镍催化剂(NiBr2·二甘醇二甲醚)可以在异常温和的条件下(例如,-20°C)实现烷基溴与亲核硅试剂的偶联;特别值得注意的是我们能够使用未活化的叔烷基卤化物作为亲电偶联伙伴,这在交叉偶联化学领域还比较少见。立体化学、相对反应性和自由基陷阱研究与 CX 键裂解的均裂途径一致。
Nickel-Catalyzed Coupling Reactions of Alkyl Electrophiles, Including Unactivated Tertiary Halides, To Generate Carbon–Boron Bonds
作者:Alexander S. Dudnik、Gregory C. Fu
DOI:10.1021/ja304068t
日期:2012.6.27
examples of coupling reactions of unactivated tertiaryalkyl 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 alkylhalides with diboron reagents to furnish alkylboronates, a family of compounds with substantial
通过使用NiBr(2)·二甘醇二甲醚原位形成的催化剂和pybox配体(两者均可商购),我们实现了未活化叔烷基亲电试剂偶联反应的第一个实例,并取得了首次成功镍催化偶联产生除 CC 键以外的键。具体来说,我们已经确定,这种催化剂在温和条件下完成了未活化的叔、仲和伯烷基卤化物与二硼试剂的宫浦型硼酸化反应,以提供烷基硼酸酯,这是一个具有实质性(并扩大)效用的化合物家族;事实上,叔烷基溴的 umpolung 硼酸化可以在低至 -10 °C 的温度下实现。该方法表现出良好的官能团兼容性和区域特异性,这两者都可能是合成烷基硼酸酯的传统方法的问题。与看似相关的镍催化 CC 键形成过程相反,在这种镍催化的 CB 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;鉴于两种转化都可能遵循氧化加成的内球电子转移途径,这种差异尤其值得注意。
Gas-phase pyrolytic reaction of 3-anilino-1-propanol derivatives: kinetic and mechanistic study
3-Anilino-1-propanol derivatives 4a–c, 5a–c, 6a–c containing primary, secondary, and tertiary alcohols and PhNH, PhNMe, and (Ph)2N were prepared and subjected to gas-phase pyrolysis in a static reaction system. The pyrolytic reactions were homogeneous and followed a first-order rate equation. Reactions took place by retro-ene process, with the exception of compounds 5a and 5b. Analysis of the pyrolysate
Anti‐Markovnikov Hydroamination and Hydroalkoxylation of Allylic Alcohols Promoted by a Simple Rare‐Earth Metal Trialkyl Complex
作者:Xiancui Zhu、Jinrong Sun、Zhixin Wu、Dianjun Guo、Shuangliu Zhou、Shaowu Wang
DOI:10.1002/adsc.202301142
日期:2024.3.19
hydroalkoxylation of allylic alcohols catalyzed by a simple catalyst Y(CH2SiMe3)3(THF)2 has been developed, providing a variety of γ-amino and γ-alkoxy alcohols in good yields under mild conditions. Moreover, this protocol is applied to the synthesis of drug molecules Propipocaine and Proroxan. The rare-earth catalyst features readily available, wide substrate compatability, exclusive anti-Markovnikov selectivity