Phosphoramidite accelerated copper(i)-catalyzed [3 + 2] cycloadditions of azides and alkynes
作者:Lachlan S. Campbell-Verduyn、Leila Mirfeizi、Rudi A. Dierckx、Philip H. Elsinga、Ben L. Feringa
DOI:10.1039/b822994e
日期:——
Monodentate phosphoramidite ligands are used to accelerate the copper(i)-catalyzed 1,3-dipolar cycloaddition of azides and alkynes (CuAAC) rapidly yielding a wide variety of functionalized 1,4-disubstituted-1,2,3-triazoles; Cu(i) and Cu(ii) salts both function as the copper source in aqueous solution to provide excellent yields.
Visible‐Light‐Mediated Click Chemistry for Highly Regioselective Azide–Alkyne Cycloaddition by a Photoredox Electron‐Transfer Strategy
作者:Zheng‐Guang Wu、Xiang‐Ji Liao、Li Yuan、Yi Wang、You‐Xuan Zheng、Jing‐Lin Zuo、Yi Pan
DOI:10.1002/chem.202000252
日期:2020.5.4
Clickchemistry focuses on the development of highly selective reactions using simple precursors for the exquisite synthesis of molecules. Undisputedly, the CuI -catalyzed azide-alkynecycloaddition (CuAAC) is one of the most valuable examples of clickchemistry, but it suffers from some limitations as it requires additional reducing agents and ligands as well as cytotoxic copper. Here, we demonstrate
Catalyst-Free Aromatic Radiofluorination via Oxidized Iodoarene Precursors
作者:Young-Do Kwon、Jeongmin Son、Joong-Hyun Chun
DOI:10.1021/acs.orglett.8b03450
日期:2018.12.21
Oxidizediodoarenes (OIAs), prepared via mCPBA-mediated oxidation, have been demonstrated as versatile precursors for the synthesis of [18F]fluoroarenes in the absence of catalysts. OIAs have been identified as intermediates in single-pot syntheses of iodonium salts and ylides but have never been recognized as radiofluorinationprecursors. Here, the isolated OIAs were used without any catalysts to
Organic synthesis via magnetic attraction: benign and sustainable protocols using magnetic nanoferrites
作者:R. B. Nasir Baig、Rajender S. Varma
DOI:10.1039/c2gc36455g
日期:——
Magnetic nano-catalysts have been prepared using simple modification of iron ferrites. The nm size range of these particles facilitates the catalysis process, as an increased surface area is available for the reaction; the easy separation of the catalysts by an external magnet and their recovery and reuse are additional beneficial attributes. Glutathione bearing nano-ferrites have been used as organocatalysts for the Paal–Knorr reaction and homocoupling of boronic acids. Nanoferrites, post-synthetically modified by ligands, were used to immobilize nanometals (Cu, Pd, Ru, etc.) which enabled the development of efficient, sustainable and green procedures for azide–alkynes-cycloaddition (AAC) reactions, C–S coupling, O-allylation of phenol, Heck-type reactions and hydration of nitriles.
preparation of N‐heterocycles by different routes. For instance, the Cu‐HMOP efficiently catalyzes one‐pot sequential multi‐step oxidative dehydrogenative coupling of 2‐aminobenzyl alcohol with diverse aromatic ketones to afford corresponding quinolines in excellent isolated yields (up to 97 %). Secondly, the present catalyst exhibits good aerobic oxidative dehydrogenation activity of amines to imines
在绿色化学的背景下,使用非贵金属从可再生资源合成N杂环的非均相催化在经济和环境方面引起了极大的兴趣。本文中,我们提出了一种具有纳米棒形貌的三嗪功能分级介孔有机聚合物(HMOP),以及较大的BET表面积〜1218 m 2 g -1,巨大的孔体积和γτ“; 6 mL g -1和双重微/介孔架构。随后的HMOP与氮原子的Cu配位提供了一种强大的催化剂(Cu-HMOP),可完成通过不同途径制备N-杂环的多步级联反应。例如,Cu-HMOP有效催化2-氨基苄醇与各种芳族酮的一锅顺序多步氧化脱氢偶联反应,从而以优异的分离产率(高达97%)提供相应的喹啉。其次,本发明的催化剂表现出胺对亚胺的良好的好氧氧化脱氢活性。第三,对于涉及叠氮化物-炔烃的“点击”反应,Cu-HMOP在室温下以水为溶剂,可定量获得1,4-二取代的1,2,3-三唑衍生物。