用于有机合成的金属磷化物催化剂的研究很少。我们首次提出了一种定义明确的纳米钴磷化物 (nano-Co 2 P),它可以作为一种新型催化剂,用于将腈类氢化成伯胺。虽然用于腈加氢的地球上丰富的金属催化剂通常具有空气不稳定性(自燃性)、低活性和需要苛刻的反应条件,但 nano-Co 2 P 显示出空气稳定性和非常高的戊腈加氢活性。优秀的营业额超过 58000,比之前报道的高出 20 到 500 倍以上。此外,纳米Co 2即使在仅 1 bar 的 H 2压力下, P 也能有效地促进多种腈(包括二腈和四腈)氢化成相应的伯胺,远比常规反应条件温和。详细的光谱研究表明,纳米 Co 2 P的高性能归因于其空气稳定的金属性质,以及通过钴的磷化作用使 Co 在费米能级附近的 d 电子密度增加,从而导致加速腈和H 2的活化。这种磷化为设计在高效和环境友好的氢化中具有高活性和稳定性的先进催化剂提供了一种有前景的方法。
phosphide catalysts for organic synthesis is rare. We present, for the first time, a well-defined nano-cobalt phosphide (nano-Co2P) that can serve as a new class of catalysts for the hydrogenation of nitriles to primary amines. While earth-abundant metal catalysts for nitrile hydrogenation generally suffer from air-instability (pyrophoricity), low activity and the need for harsh reaction conditions
用于有机合成的金属磷化物催化剂的研究很少。我们首次提出了一种定义明确的纳米钴磷化物 (nano-Co 2 P),它可以作为一种新型催化剂,用于将腈类氢化成伯胺。虽然用于腈加氢的地球上丰富的金属催化剂通常具有空气不稳定性(自燃性)、低活性和需要苛刻的反应条件,但 nano-Co 2 P 显示出空气稳定性和非常高的戊腈加氢活性。优秀的营业额超过 58000,比之前报道的高出 20 到 500 倍以上。此外,纳米Co 2即使在仅 1 bar 的 H 2压力下, P 也能有效地促进多种腈(包括二腈和四腈)氢化成相应的伯胺,远比常规反应条件温和。详细的光谱研究表明,纳米 Co 2 P的高性能归因于其空气稳定的金属性质,以及通过钴的磷化作用使 Co 在费米能级附近的 d 电子密度增加,从而导致加速腈和H 2的活化。这种磷化为设计在高效和环境友好的氢化中具有高活性和稳定性的先进催化剂提供了一种有前景的方法。
Boron-Catalyzed Silylative Reduction of Nitriles in Accessing Primary Amines and Imines
Silylative reduction of nitriles was studied under transition metal-free conditions by using B(C6F5)3 as a catalyst with hydrosilanes as a reductant. Alkyl and (hetero)aryl nitriles were efficiently converted to primaryamines or imines under mild conditions. The choice of silanes was found to determine the selectivity: while a full reduction of nitriles was highly facile, the use of sterically bulky
在无过渡金属的条件下,通过使用B(C 6 F 5)3作为催化剂,以氢硅烷作为还原剂,研究了腈的甲硅烷基化还原反应。在温和的条件下,烷基和(杂)芳基腈被有效地转化为伯胺或亚胺。发现硅烷的选择决定了选择性:虽然腈的完全还原非常容易,但是使用空间大体积的硅烷允许部分还原,从而生成N-甲硅烷基亚胺。
Glycoluril‐Derived Molecular Clips are Potent and Selective Receptors for Cationic Dyes in Water
Molecularclip 1 remains monomeric in water and engages in host–guest recognition processes with suitable guests. We report the Ka values for 32 1⋅guest complexes measured by 1H NMR, UV/Vis, and fluorescence titrations. The cavity of 1 is shaped by aromatic surfaces of negative electrostatic potential and therefore displays high affinity and selectivity for planar and cationic aromatic guests that
分子夹1在水中仍然是单体,并与合适的客人一起参与宿主-客体识别过程。我们报告了通过1 H NMR,UV / Vis和荧光滴定法测得的32个1⋅客体配合物的K a值。1的腔体由负电势的芳族表面形成,因此对平面和阳离子芳族客体显示出高亲和力和选择性,这使其与CB [ n ]受体相区别,后者比脂族客体更喜欢脂肪族。静电作用在识别过程中起着主要作用,在此过程中,铵离子和C = O的1个基团之间可能发生离子-偶极相互作用。情况下,SO之间3 -基团的1和在来宾悬垂阳离子基团,和空腔内1由阳离子-π相互作用。宿主1对具有大的平面芳族表面(例如萘二酰亚胺NDI +和per二酰亚胺PDI +)和衍生自a啶的阳离子染料(例如亚甲基蓝和天蓝色A)表现出较高的亲和力。通过比较类似的中性和阳离子客体(例如,亚甲基紫与亚甲基蓝;喹啉与N-甲基喹啉鎓; a啶与N-甲基ac啶;中性红与中性红H +)可以确定阳离子-π相
A State‐of‐the‐Art Heterogeneous Catalyst for Efficient and General Nitrile Hydrogenation
conditions (e.g. 70 °C, 20 bar H2). The advantage of this novel catalyticmaterial is showcased for industrially important substrates, including adipodinitrile, picolinonitrile, and fatty acid nitriles. Notably, the developed system outperformed all other tested commercial catalysts, for example, Raney Nickel and even noble‐metal‐basedsystems in these transformations.
制备了由金属氧化物和几丁质衍生的碳组成的钴掺杂杂化材料,对其进行了表征并进行了工业相关腈加氢测试。在700°C下热解后,负载在MgO上的最佳催化剂显示了用碳包裹的Co纳米颗粒修饰的氧化镁纳米立方体。这种特殊的结构允许在温和的条件下(例如70°C,20 bar H 2)将各种苛刻的腈选择性氢化为相应的伯胺。)。这种新型催化材料的优势在工业上重要的底物上得到了展示,这些底物包括己二腈,吡咯腈和脂肪酸腈。值得注意的是,在这些转换中,开发的系统优于所有其他经过测试的商业催化剂,例如阮内镍,甚至贵金属基系统。
Selective Hydrogenation of Nitriles to Primary Amines Catalyzed by a Polysilane/SiO<sub>2</sub>
-Supported Palladium Catalyst under Continuous-Flow Conditions
Hydrogenation of nitriles to primary amines with heterogeneous catalysts under liquid‐phase continuous‐flow conditions is described. Newly developed polysilane/SiO2‐supported Pd was found to be an effective catalyst and various nitriles were converted into primary amine salts in almost quantitative yields under mild reaction conditions. Interestingly, a complex mixture was obtained under batch conditions