A Rationally Designed Upconversion Nanoprobe for in Vivo Detection of Hydroxyl Radical
摘要:
The detection of center dot OH in live organisms is crucial to the understanding of its physiological and pathological roles; while this is too challenging because of the extremely low concentration and high reactivity of the species in the body. Herein, we report the rational design and fabrication of an NIR-light excited luminescence resonance energy transfer-based nanoprobe, which for the first time realizes the in vivo detection of center dot OH. The nanoprobe is composed of two moieties: upconversion nanoparticles with sandwich structure and bared surface as the energy donor; and mOG, a modified azo dye with tunable light absorption, as both the energy acceptor and the center dot OH recognizing ligand. The as-constructed nanoprobe exhibited ultrahigh sensitivity (with the quantification limit down to 1.2 femtomolar, several orders of magnitude lower than that of most previous center dot OH probes), good biocompatibility, and specificity. It was successfully used for monitoring [center dot OH] levels in live cells and tissues.
Cyclic (Alkyl)(amino)carbene Ligand-Promoted Nitro Deoxygenative Hydroboration with Chromium Catalysis: Scope, Mechanism, and Applications
作者:Lixing Zhao、Chenyang Hu、Xuefeng Cong、Gongda Deng、Liu Leo Liu、Meiming Luo、Xiaoming Zeng
DOI:10.1021/jacs.0c12318
日期:2021.1.27
Transition metal catalysis that utilizes N-heterocycliccarbenes as noninnocent ligands in promoting transformations has not been well studied. We report here a cyclic (alkyl)(amino)carbene (CAAC) ligand-promoted nitro deoxygenative hydroboration with cost-effective chromium catalysis. Using 1 mol % of CAAC-Cr precatalyst, the addition of HBpin to nitro scaffolds leads to deoxygenation, allowing for
Transfer Hydrogenation of Ketones, Nitriles, and Esters Catalyzed by a Half-Sandwich Complex of Ruthenium
作者:Sun-Hwa Lee、Georgii I. Nikonov
DOI:10.1002/cctc.201402780
日期:2015.1
Half‐sandwich complexes [Cp(PiPr3)Ru(CH3CN)2]PF6 (1; Cp=cyclopentadienyl) and [Cp*(phen)Ru(CH3CN)]PF6 (2; Cp*=pentamethylcyclopentadienyl, phen=phenanthroline) catalyse the transferhydrogenation of ketones to alcohols, aldimines to amines, and nitriles to imines under mild conditions. In the latter process, the imine products come from the coupling of the amines formed initially with acetone derived
Cobalt-Catalyzed and Lewis Acid-Assisted Nitrile Hydrogenation to Primary Amines: A Combined Effort
作者:Kenan Tokmic、Bailey J. Jackson、Andrea Salazar、Toby J. Woods、Alison R. Fout
DOI:10.1021/jacs.7b07368
日期:2017.9.27
The selective hydrogenation of nitriles to primary amines using a bench-stable cobalt precatalyst under 4 atm of H2 is reported herein. The catalyst precursor was reduced in situ using NaHBEt3, and the resulting Lewis acid formed, BEt3, was found to be integral to the observed catalysis. Mechanistic insights gleaned from para-hydrogen induced polarization (PHIP) transfer NMR studies revealed that the
本文报道了在 4 个大气压的 H 2 下使用实验室稳定的钴预催化剂将腈选择性氢化成伯胺。使用 NaHBEt 3 原位还原催化剂前体,并且发现所形成的路易斯酸 BEt 3 是观察到的催化作用的组成部分。从对氢诱导极化 (PHIP) 转移 NMR 研究中收集到的机理见解表明,腈的成对氢化是通过 Co(I/III) 氧化还原过程进行的。
Cobalt‐Catalyzed Deoxygenative Hydroboration of Nitro Compounds and Applications to One‐Pot Synthesis of Aldimines and Amides
作者:Kristina A. Gudun、Raikhan Zakarina、Medet Segizbayev、Davit Hayrapetyan、Ainur Slamova、Andrey Y. Khalimon
DOI:10.1002/adsc.202101043
日期:2022.2
The commercially available and bench-stable Co(acac)2 ligated with bis[(2-diphenylphosphino)phenyl] ether (dpephos) was employed for selective room temperature hydroboration of nitro compounds with HBPin (TOF up to 4615 h−1), tolerating halide, hydroxy, amino, ether, ester, lactone, amide and heteroaromatic functionalities. These reactions offered a direct access to a variety of N-borylamines RN(H)BPin
The selective catalytic hydrogenation of nitriles to primary amines with the well-defined Fe(PNPCy) pincer complex 2 is reported. This iron pincer catalyst shows superior catalytic activity and selectivity in the reduction of various nitriles including industrially relevant adipodinitrile in high yields under relatively mild conditions.