861573-48-0Relevant articles and documents
Benzylic C-H Azidation Using the Zhdankin Reagent and a Copper Photoredox Catalyst
Rabet, Pauline T. G.,Fumagalli, Gabriele,Boyd, Scott,Greaney, Michael F.
, p. 1646 - 1649 (2016)
An azidation method for C-N bond formation at benzylic C-H positions is described using copper-catalyzed visible light photochemistry and the Zhdankin azidoiodinane reagent. The method is applicable to a wide range of substrates bearing different functional groups and having a primary, secondary, or tertiary benzylic position, and is thought to proceed through a radical chain reaction.
Catalytic Staudinger Reduction at Room Temperature
Lenstra, Danny C.,Wolf, Joris J.,Mecinovi?, Jasmin
, p. 6536 - 6545 (2019/05/24)
We report an efficient catalytic Staudinger reduction at room temperature that enables the preparation of a structurally diverse set of amines from azides in excellent yields. The reaction is based on the use of catalytic amounts of triphenylphosphine as a phosphine source and diphenyldisiloxane as a reducing agent. Our catalytic Staudinger reduction exhibits a high chemoselectivity, as exemplified by reduction of azides over other common functionalities, including nitriles, alkenes, alkynes, esters, and ketones.
Synthesis of novel pyrazoline-based bis(1,2,3-triazole) scaffolds via click chemistry
Kiran, Kothuri,Ashok, Dongamanti,Rao, Boddu Ananda,Sarasija, Madderla,Rao, Alapati Srinivas
, p. 241 - 251 (2017/05/09)
A series of novel bis(1,2,3-triazoles) derivatives 7a-m were synthesized by the 1,3-dipolar cycloaddition (click-reaction) of 1-methyl-3,5-bis(2-(prop-2-yn-1-yloxy)phenyl)-4,5-dihydro-1H-pyrazole (5) with various aralkyl azides 6a-m in the presence of sod
A concise synthesis of quinolinium, and biquinolinium salts and biquinolines from benzylic azides and alkenes promoted by copper(II) species
Chen, Wei-Chen,Gandeepan, Parthasarathy,Tsai, Chia-Hung,Luo, Ching-Zong,Rajamalli, Pachaiyappan,Cheng, Chien-Hong
, p. 63390 - 63397 (2016/07/19)
A novel copper-promoted multiple aza-[4 + 2] cycloaddition reaction of N-methyleneanilines in situ generated from benzylic azide and alkenes afforded quinolinium salts, biquinolinium salts, biquinolines or substituted quinolines depending on the substitution on the phenyl ring of benzylic azide. The reaction of para substituted benzylic azides and 2 equivalents of alkenes afforded the corresponding substituted quinolinium salts, while benzylic azides without a para substituent provided biquinolinium salts. The copper-promoted cycloaddition reaction also allows biquinoline products to be obtained from ortho-substituted benzylic azides. These reactions work well with both terminal and internal alkenes. Unsymmetrical internal alkene reactions proceed with high regioselectivity. The reaction is likely started by Lewis acidic CuII-assisted rearrangement of benzylic azide to N-methyleneaniline, followed by a [4 + 2] cycloaddition with alkene. Detailed mechanistic studies suggest that the biquinoline and biquinolinium salts are likely formed via radical processes.
Metal-catalysed azidation of tertiary C-H bonds suitable for late-stage functionalization
Sharma, Ankit,Hartwig, John F.
, p. 600 - 604 (2015/03/04)
Many enzymes oxidize unactivated aliphatic C-H bonds selectively to form alcohols; however, biological systems do not possess enzymes that catalyse the analogous aminations of C-H bonds. The absence of such enzymes limits the discovery of potential medicinal candidates because nitrogen-containing groups are crucial to the biological activity of therapeutic agents and clinically useful natural products. In one prominent example illustrating the importance of incorporating nitrogen-based functionality, the conversion of the ketone of erythromycin to the -N(Me)CH2 - group in azithromycin leads to a compound that can be dosed once daily with a shorter treatment time. For such reasons, synthetic chemists have sought catalysts that directly convert C-H bonds to C-N bonds. Most currently used catalysts for C-H bond amination are ill suited to the intermolecular functionalization of complex molecules because they require excess substrate or directing groups, harsh reaction conditions, weak or acidic C-H bonds, or reagents containing specialized groups on the nitrogen atom. Among C-H bond amination reactions, those forming a C-N bond at a tertiary alkyl group would be particularly valuable, because this linkage is difficult to form from ketones or alcohols that might be created in a biosynthetic pathway by oxidation. Here we report a mild, selective, iron-catalysed azidation of tertiary C-H bonds that occurs without excess of the valuable substrate. The reaction tolerates aqueous environments and is suitable for the functionalization of complex structures in the late stages of a multistep synthesis. Moreover, this azidation makes it possible to install a range of nitrogen-based functional groups, including those from Huisgen 'click' cycloadditions and the Staudinger ligation. We anticipate that these reactions will create opportunities to modify natural products, their precursors and their derivatives to produce analogues that contain different polarity and charge as a result of nitrogen-containing groups. It could also be used to help identify targets of biologically active molecules by creating a point of attachment - for example, to fluorescent tags or 'handles' for affinity chromatography - directly on complex molecular structures.
Copper promoted synthesis of substituted quinolines from benzylic azides and alkynes
Luo, Ching-Zong,Gandeepan, Parthasarathy,Wu, Yun-Ching,Chen, Wei-Chen,Cheng, Chien-Hong
, p. 106012 - 106018 (2015/12/30)
A novel copper promoted synthesis of substituted quinolines from various benzylic azides and internal alkynes has been demonstrated. The reaction features a broad substrate scope, high product yields and excellent regioselectivity. In contrast to the known two-step process of acid promoted [4 + 2] cycloaddition reaction and oxidation, the present methodology allows the synthesis of quinolines in a single step under neutral reaction conditions and can be applied to the synthesis of biologically active 6-chloro-2,3-dimethyl-4-phenylquinoline (antiparasitic agent) and 3,4-diphenylquinolin-2(1H)-one (p38αMAP kinase inhibitor). A plausible reaction mechanism involves rearrangement of benzylic azide to N-arylimine (Schmidt reaction) followed by intermolecular [4 + 2] cycloaddition with internal alkynes.
C5-Modified nucleosides exhibiting anticancer activity
Lee, Yoon-Suk,Park, Sun Min,Kim, Hwan Mook,Park, Song-Kyu,Lee, Kiho,Lee, Chang Woo,Kim, Byeang Hyean
scheme or table, p. 4688 - 4691 (2010/04/28)
We describe (i) a simple method for the synthesis of C5-modified nucleosides from 5-iodo-2′-deoxyuridine and (ii) their activity against six types of human cancer cell lines (HCT15, MM231, NCI-H23, NUGC-3, PC-3, ACHN). We generated nitrile oxides in situ from oximes using a commercial bleaching agent; their cycloadditions with 5-ethynyl-2′-deoxyuridine yielded isoxazole derivatives possessing activity against the cancer cell lines. We synthesized several azides from benzylic bromides and their click reactions with 5-ethynyl-2′-deoxyuridine provided triazole derivatives.
