efficient copper-catalyzed selectivetransferhydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine–BH3 complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to
Aluminum Metal–Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis
作者:Neha Antil、Ajay Kumar、Naved Akhtar、Rajashree Newar、Wahida Begum、Ashutosh Dwivedi、Kuntal Manna
DOI:10.1021/acscatal.0c04379
日期:2021.4.2
and heterogeneous earth-abundant metal catalysts is essential for environmentally friendly chemical synthesis. We report a highly efficient, chemoselective, and reusable single-site nickel(II) hydride catalyst based on robust and porous aluminum metal–organic frameworks (MOFs) (DUT-5) for hydrogenation of nitro and nitrile compounds to the corresponding amines and hydrogenolysis of arylethers under
化学选择性的和非均质的富含地球的金属催化剂的开发对于环境友好的化学合成至关重要。我们报告了一种高效,化学选择性和可重复使用的单中心氢化镍(II)氢化物催化剂,该催化剂基于坚固且多孔的铝金属有机骨架(MOFs)(DUT-5),用于将硝基和腈化合物加氢成相应的胺并进行氢解温和条件下制备芳基醚。镍-氢化物催化剂的制备是通过的氢氧化铝次级结构单元的金属化的Al具有(μ的式DUT-5的(事业部)2 -OH)(BPDC)(BPDC = 4,4'-联苯双酯)与NIBR 2然后与NaEt 3反应BH。DUT-5-NiH具有广泛的底物范围,在1 bar H 2下氢化芳族和脂肪族硝基和腈化合物时,具有出色的官能团耐受性至少可以回收再利用10次。通过改变腈氢化的反应条件,还选择性地提供了对称或不对称的仲胺。实验和计算研究表明,在营业额限制步骤中,镍与镍的可逆腈配位是可逆的,然后将1,2-的配位腈插入氢化镍中。此
Factors Influencing the Regioselectivity of the Oxidation of Asymmetric Secondary Amines with Singlet Oxygen
作者:Dmitry B. Ushakov、Matthew B. Plutschack、Kerry Gilmore、Peter H. Seeberger
DOI:10.1002/chem.201500121
日期:2015.4.20
functionalization of amines. However, there are still several mechanistic uncertainties, particularly the factors governing the regioselectivity of the oxidation of asymmetric secondary amines and the oxidation rates of mixed primary amines. Herein, it is reported that singlet‐oxygen‐mediated oxidation of 1° and 2° amines is sensitive to the strength of the α‐CH bond and steric factors. Estimation of the
A concentrated sample having enhanced concentration of the one or more different populations of target rare molecules is incubated with, for each different population of target rare molecules, a particulate or non-particulate affinity agent that comprises a specific binding partner that is specific for and binds to a target rare molecule. The affinity agent comprises a mass spectrometry (MS) label precursor or a first alteration agent, which either facilitates the formation of an MS label from the MS label precursor or releases an entity that comprises the MS label precursor from the affinity agent. The MS label corresponds to one of the populations of target rare molecules. A second alteration agent is employed if the first alteration agent does not facilitate the formation of an MS label from the MS label precursor. MS analysis is used to determine each different MS label.
针对每种不同的目标稀有分子群,将具有一个或多个不同目标稀有分子群的更高浓度的浓缩样品与微粒或非微粒亲和剂进行孵育,亲和剂包括特异性结合伴侣,该特异性结合伴侣对目标稀有分子具有特异性并能与目标稀有分子结合。亲和剂包括质谱(MS)标签前体或第一改变剂,第一改变剂可促进质谱标签前体形成 MS 标签,或从亲和剂中释放出包含 MS 标签前体的实体。MS 标记与目标稀有分子群之一相对应。如果第一种改变剂不能促进 MS 标签前体形成 MS 标签,则使用第二种改变剂。MS 分析用于确定每个不同的 MS 标签。
Carbonic Anhydrase-Encoded Dynamic Constitutional Libraries: Toward the Discovery of Isozyme-Specific Inhibitors
作者:Gihane Nasr、Eddy Petit、Daniela Vullo、Jean-Yves Winum、Claudiu T. Supuran、Mihail Barboiu
DOI:10.1021/jm900449v
日期:2009.8.13
A constitutional dynamic library (CDL) was generated under thermodynamic control by using the amino-carbonyl/imine interconversion as reversible chemistry, combined with noncovalent bonding within the active site of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). Considering the pharmacological importance to find isoform-selective CA inhibitors (CAIs), two of the 15 human (h) isoform, i.e., hCAI and hCAII, have been subjected to a parallel screening of the same CDL. The use of parallel constitutional screening of CDL chemistry for the discovery of enzyme inhibitors is straightforward and it might provide initial insights toward the generation of efficient classes of selective, high affinity inhibitors. We demonstrate here that the high selectivity and specificity of inhibiting the hCAI and hCAII. isozymes with some of the detected hits may be used to describe a complex constitutional behavior through component selection from the dynamic library, driven by the selective binding to the specific isoform active site. These results also point to the possibility of modulating the drug discovery methods by constitutional recomposition induced by a specific enzymatic target.