Air‐Stable Fe<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>‐EDTA‐Ni(0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki‐Miyaura and Heck Cross‐Coupling via Aryl Sulfamates and Carbamates
The synthesis of inexpensive and novel air‐stable Ni(0) nanoparticles immobilized on the EDTA‐modified Fe3O4@SiO2 nanocatalyst was investigated in Suzuki‐Miyaura and Heckcross‐couplingreactions. This catalytic system displayed a greatly improved substrate scope for the carbon–carbon bond formations starting from a wide range of green and economical electrophiles aryl and heteroaryl carbamates and
廉价且新颖的,稳定的,稳定在EDTA修饰的Fe 3 O 4 @SiO 2上的Ni(0)纳米颗粒的合成在Suzuki-Miyaura和Heck交叉偶联反应中研究了纳米催化剂。该催化体系通过在温和,操作简单的反应条件下通过高效方法,从广泛的绿色和经济亲电氨基甲酸酯和杂芳基氨基甲酸酯和氨基磺酸盐开始,显着改善了碳-碳键形成的底物范围。合成的多相催化剂还通过FT-IR,TEM,XRD,DLS,FE-SEM,UV-Vis,EDX,XPS,TGA,NMR,VSM,ICP和元素分析技术进行了全面表征。可以通过外部磁场容易地回收异质磁性纳米催化剂,并且在催化剂的沥滤可忽略不计并且活性没有实质性降低的情况下,至少七次重复用于接下来的反应至少七次。所有这些亮点使本协议变得有趣,
Nickel-Catalyzed Amination of Aryl Sulfamates and Carbamates Using an Air-Stable Precatalyst
作者:Liana Hie、Stephen D. Ramgren、Tehetena Mesganaw、Neil K. Garg
DOI:10.1021/ol301847m
日期:2012.8.17
A facile nickel-catalyzed method to achieve the amination of synthetically useful arylsulfamates and carbamates is reported. Contrary to most Ni-catalyzed amination reactions, this user-friendly approach relies on an air-stable Ni(II) precatalyst, which, when employed with a mild reducing agent, efficiently delivers aminated products in good to excellent yields. The scope of the method is broad with
报道了一种简便的镍催化方法来实现合成有用的氨基磺酸芳基酯和氨基甲酸酯的胺化。与大多数 Ni 催化的胺化反应相反,这种用户友好的方法依赖于空气稳定的 Ni(II) 预催化剂,当它与温和的还原剂一起使用时,可以有效地以良好到优异的产率提供胺化产物。该方法的范围就两个偶联伙伴而言都是广泛的,并且包括杂环底物。
Remarkably Efficient Iridium Catalysts for Directed C(sp<sup>2</sup>)–H and C(sp<sup>3</sup>)–H Borylation of Diverse Classes of Substrates
aliphatic substrates for selective C(sp3)–H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C–H bonds. A number of late-stage C–H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)–H and C(sp3)–Hborylations enabling the method more general
The reactions of o-lithiated O-aryl N,N-diethylcarbamates with different C–N multiple bond electrophiles have been thoroughly studied. A 1,5-O → N carbamoyl shift, a new variation of the anionic Fries-type rearrangement, takes place when nitriles, imines, or alkylcarbodiimides are employed. In these cases, the carbamoyl group plays a dual role as a directing group, building up a variety of functional
<i>N</i>-Arylation of (hetero)arylamines using aryl sulfamates and carbamates <i>via</i> C–O bond activation enabled by a reusable and durable nickel(0) catalyst
elemental analysis techniques. The reaction proceeded via carbon–oxygen bondcleavage of (hetero)aryl carbamates and sulfamates under simple and mild conditions without the use of any external ligands. This method demonstrated functional group tolerance in the N-arylation of various nitrogen-containing compounds as well as aliphatic amines, anilines, pyrroles, pyrazoles, imidazoles, indoles, and indazoles
已经开发出了一种有效且通用的芳基胺化方案,使用了可磁回收的Ni(0)基纳米催化剂。该新型稳定催化剂是在EDTA改性的Fe 3 O 4 @SiO 2上制备的,并通过FT-IR,EDX,TEM,XRD,DLS,FE-SEM,XPS,NMR,TGA,VSM,ICP和元素分析技术进行了研究。该反应通过在简单温和的条件下不使用任何外部配体的情况下,通过(杂)芳基氨基甲酸酯和氨基磺酸酯的碳-氧键裂解来进行。该方法证明了N中的官能团耐受性各种含氮化合物以及脂肪族胺,苯胺,吡咯,吡唑,咪唑,吲哚和吲唑的芳基化,收率良好。此外,该催化剂可以通过使用外部磁场容易地回收,并且可以直接重复使用至少六次而不会显着降低其活性。