An Alternative Synthesis of 2-Alkylidene-3,4-dihydro-2H-1,4-benzoxazines by Intramolecular Gold-Catalyzed Hydroalkoxylation of 2-(Prop-2-yn-1-ylamino)phenols

Manzo, Angelo Maria; Perboni, Alcide; Broggini, Gianluigi; Rigamonti, Micol

doi:10.1055/s-0030-1258346

Cited by 15 publications

(7 citation statements)

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“…Manzo and coworkers further demonstrated this selectivity pattern in their intramolecular hydroalkoxylation of 2-alkynylsubstituted phenols 38 (Scheme 11). 33 Treatment with AuCl and potassium carbonate induced a 6-exo-dig cyclization of the phenol onto the tethered alkyne to exclusively afford the corresponding enol ether products 39.…”

Section: Intramolecular Hydroalkoxylationmentioning

confidence: 99%

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

2015

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Over the past decade and a half, homogenous gold catalysis has emerged as a diverse and rich field of research resulting in the continuous development of new methods for organic synthesis. The activation of alkynes towards nucleophilic attack by Au(I) and Au(III) complexes is a well-established mode of reactivity and the gold-catalyzed hydration and hydroalkoxylation of alkynes are two of the more well-explored reaction pathways. Although these classes of reactions have seen continuous development since their initial reports, achieving regioselectivity persists as one of the most challenging issues for this chemistry. This article aims to draw attention to the general problem of regioselectivity in these reactions. A select set of examples is presented to highlight the challenges and survey some of the strategies employed to address this problem.

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Section: Intramolecular Hydroalkoxylationmentioning

confidence: 99%

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

2015

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“…The key step was the introduction of the acetylenic group on the aromatic framework. We used an elegant and rapid route to synthesize the 2‐(prop‐2‐yn‐1‐ylamino)phenol intermediate 2 . By stirring propargyl bromide with a large excess of 2‐aminophenol in absolute ethanol during 4 days, we obtained 2 in 82%.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and preliminary biological evaluation of the first^99mTc(I)-specific semi-rigid tridentate ligand based on a click chemistry strategy

Guizani

Saied

Picard

et al. 2014

J. Label Compd. Radiopharm

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A novel bifunctional chelating agent based on a click chemistry strategy has been synthesized and characterized on the basis of spectroscopic techniques. The metal chelating part of this new class of tridentate N2O ligand combined a triazole unit and an aromatic ring. This latter semi-rigid framework induced a pre-organization of the chelating cavity, improving the stability of the corresponding metallic complexes (M = (99m) Tc, Re). Thus, the (99m) Tc(CO)3 complex, obtained with good yield and excellent radiochemical purity (>90%), exhibited a high in vitro serum stability. Tissue biodistribution in normal mice showed a rapid clearance, no long-term retention in organs and no in vivo reoxidation of technetium-99m, making this compound a promising (99m)Tc-chelating system.

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“…Intermediate Synthesis: Methyl azidoacetate, 2‐(prop‐2‐yn‐1‐ylamino)phenol ( 1 ), 2‐[( tert ‐butyldimethylsilyl)oxy]aniline ( 2 ), 1‐azido‐4‐nitrobenzene ( 8 ) and the rhenium precursor [Re(CO) 3 (H 2 O) 3 ]Br were synthesized according to literature protocols.…”

Section: Methodsmentioning

confidence: 99%

Rhenium Complexes Based on an N₂O Tridentate Click Scaffold: From Synthesis, Structural and Theoretical Characterization to a Radiolabelling Study

et al. 2016

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International audienceA general synthetic approach to a novel range of semirigid bifunctional chelating agents (BCAs) that include an aromatic ring and a triazolyl moiety in the chelating unit has been investigated for the fac-[M(CO)3]+ core (M = 185/187Re or 188Re). The strategy includes the facile preparation of these N2O ligands bearing various functionalized arms (carboxylate, terminal alkyne, aromatic amine). The reaction of commercial [Re(CO)5Cl] ₒr a freshly prepared [Re(OH2)3(CO)3]+ precursor_ with our BCAs in methanol led to the formation of stable neutral tricarbonylrhenium complexes of general formula [Re(CO)3(L)] (LH = 5, 10, 11) in high yields. These compounds were characterized by IR and NMR spectroscopy, mass spectrometry, electrochemistry, and X-ray crystallography for [Re(CO)3(5–H)] and [Re(CO)3(11–H)] as well as by DFT calculations. The analogous rhenium-188 complexes [188Re(CO)3(5)] and [188Re(CO)3(11–H)] were also prepared, in acceptable to excellent yields, by the reaction of 5 or 11 with the fac-[188Re(OH2)3(CO)3]+ precursor in methanol at 80 °C. The structural identities of the radioactive complexes were assessed by HPLC studies. The good affinity of these click ligands for the ReI core combined with the ease of their derivatization make this chelating system promising for the conception of target-specific radiopharmaceuticals for therapeutic purposes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

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An Alternative Synthesis of 2-Alkylidene-3,4-dihydro-2H-1,4-benzoxazines by Intramolecular Gold-Catalyzed Hydroalkoxylation of 2-(Prop-2-yn-1-ylamino)phenols

Cited by 15 publications

References 0 publications

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

Synthesis and preliminary biological evaluation of the first^99mTc(I)-specific semi-rigid tridentate ligand based on a click chemistry strategy

Rhenium Complexes Based on an N₂O Tridentate Click Scaffold: From Synthesis, Structural and Theoretical Characterization to a Radiolabelling Study

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An Alternative Synthesis of 2-Alkylidene-3,4-dihydro-2H-1,4-benzoxazines by Intramolecular Gold-Catalyzed Hydroalkoxylation of 2-(Prop-2-yn-1-ylamino)phenols

Cited by 15 publications

References 0 publications

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

Regioselectivity in the Au-catalyzed hydration and hydroalkoxylation of alkynes

Synthesis and preliminary biological evaluation of the first99mTc(I)-specific semi-rigid tridentate ligand based on a click chemistry strategy

Rhenium Complexes Based on an N2O Tridentate Click Scaffold: From Synthesis, Structural and Theoretical Characterization to a Radiolabelling Study

Contact Info

Product

Resources

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Synthesis and preliminary biological evaluation of the first^99mTc(I)-specific semi-rigid tridentate ligand based on a click chemistry strategy

Rhenium Complexes Based on an N₂O Tridentate Click Scaffold: From Synthesis, Structural and Theoretical Characterization to a Radiolabelling Study