Copper(<scp>i</scp>)-catalysed transfer hydrogenations with ammonia borane
作者:Eva Korytiaková、Niklas O. Thiel、Felix Pape、Johannes F. Teichert
DOI:10.1039/c6cc09067b
日期:——
Highly Z-selective alkyne transfer semihydrogenations and conjugate transferhydrogenations of enoates can be effected by employing a readily available copper(I)/N-heterocyclic carbene (NHC) complex, [IPrCuOH], in combination with ammoniaborane as a H2 equivalent.
A Simple Nickel Catalyst Enabling an
<i>E</i>
‐Selective Alkyne Semihydrogenation
作者:Niklas O. Thiel、Benyapa Kaewmee、Trung Tran Ngoc、Johannes F. Teichert
DOI:10.1002/chem.201903850
日期:2020.2.3
Stereoselective alkyne semihydrogenations are attractive approaches to alkenes, which are key building blocks for synthesis. With regards to the most atom‐economic reducing agent dihydrogen (H2), only few catalysts for the challenging E‐selectivealkyne semihydrogenation have been disclosed, each with a unique substrate scope profile. Here, we show that a commercially available nickel catalyst facilitates
立体选择性炔烃半氢化是制备烯烃的有吸引力的方法,烯烃是合成的关键组成部分。对于最具原子经济性的还原剂二氢(H 2 ),仅公开了少数用于具有挑战性的E-选择性炔烃半氢化的催化剂,每种催化剂都具有独特的底物范围特征。在这里,我们表明,市售的镍催化剂促进了多种取代内炔的E-选择性炔烃半氢化。这产生了一个简单且广泛适用的整体方案,用于使用 H 2立体选择性地访问E-烯烃,这可以作为通用的合成方法。
Tethered NHC Ligands for Stereoselective Alkyne Semihydrogenations
作者:Felix Pape、Johannes Teichert
DOI:10.1055/s-0036-1590112
日期:2017.6
N-heterocyclic carbene (NHC) complexes have been investigated, leading to a highly Z-selective transformation. The catalyst is generated from inexpensive copper(I) chloride in situ and allows catalytic semihydrogenation down to 10 bar H2. A copper(I)-catalyzed semihydrogenation of internal alkynes has been developed. A variety of oxygen- and nitrogen-tethered N-heterocyclic carbene (NHC) complexes
摘要 已经开发了铜(I)催化的内部炔烃的半氢化反应。已经研究了多种氧和氮束缚的N-杂环卡宾(NHC)配合物,从而导致高度Z选择性的转化。该催化剂由廉价的原位氯化铜(I)生成,并允许低至10 bar H 2的催化半氢化作用。 已经开发了铜(I)催化的内部炔烃的半氢化反应。已经研究了多种氧和氮束缚的N-杂环卡宾(NHC)配合物,从而导致高度Z选择性的转化。该催化剂由廉价的原位氯化铜(I)生成,并允许低至10 bar H 2的催化半氢化作用。
Stereoselective alkyne semihydrogenations with an air-stable copper(<scp>i</scp>) catalyst
作者:Niklas O. Thiel、Johannes F. Teichert
DOI:10.1039/c6ob02271e
日期:——
An air-stable and preactivated copper(I) hydroxide/N-heteroyclic carbene (NHC) complex for alkynesemihydrogenations is reported. Next to an enhanced practicability of the process, the resulting alkenes are obtained with high Z-selectivities and no overreduction to the corresponding alkanes.
Using alcohols as simple H<sub>2</sub>-equivalents for copper-catalysed transfer semihydrogenations of alkynes
作者:Trinadh Kaicharla、Birte M. Zimmermann、Martin Oestreich、Johannes F. Teichert
DOI:10.1039/c9cc06637c
日期:——
Copper(I)/N-heterocycliccarbenecomplexes enable a transfersemihydrogenation of alkynes employing simple and readily available alcohols such as isopropanol. The practical overall protocol circumvents the use of commonly employed high pressure equipment when using dihydrogen (H2) on the one hand, and avoids the generation of stoichiometric silicon-based waste on the other hand, when hydrosilanes are