Synthesis and structural characterization of a highly substituted triazine ring comprising a sterically flexible methylene linker and coordinating substituents

Werlé, Christophe; Yin, Chih-Juo Madeline; Heinemann, Frank W.; Hauser, Christina; Meyer, Karsten

doi:10.1016/j.tetlet.2017.05.083

Cited by 5 publications

(2 citation statements)

References 132 publications

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“…Prior to use, glassware was dried overnight at 130 °C, and solvents were dried, distilled, and degassed using standard methods and stored in activated 4 Å molecule sieve in the glovebox. L H 2 Br and 1-(bromomethyl)-3,5-di tert -butyl-2-methoxybenzene were made by following the literature procedure. MN(SiMe 3 ) 2 (M = Li, K) were purchased from Sigma-Aldrich and used inside the glovebox as received.…”

Section: Methodsmentioning

confidence: 99%

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂

Goswami,

Sarkar,

Mallick

et al. 2024

Organometallics

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KN(SiMe 3 ) 2 , a non-nucleophilic strong base, rarely misses deprotonating an imidazolium-2-H to give its N-heterocyclic carbene (NHC). We report a rare case of a -CH 2 -linked bifunctional imidazolium-phenol t Bu 2 -C 6 H 2 -2-CH 2 {CH(NCH�CHNAr)}]Br [LH 2 Br; Ar = 2,6-i Pr 2 −C 6 H 3 (Dipp)], whose attempted double deprotonation by KN(SiMe 3 ) 2 majorly gives an unusual substitution product [Apparently, the second KN(SiMe 3 ) 2 , instead of deprotonating the imidazolium-2-H, substitutes the whole imidazolium moiety from the benzylic carbon. Control experiments indicate a S N 1-type mechanism. But the intermediate LH, seemingly a zwitterionic imidazolium aryloxide, also shows a steady self-fragmentation by releasing free Dipp Imd to suggest a complex formative route for 1. Interestingly, LiN(SiMe 3 ) 2 in contrast favors the expected double deprotonation but further undergoes a 1,2-benzyl migration to give trimeric [Li(O-4,6-t Bu 2 -C 6 H 2 -2-CH 2 {C(NCH�CHNAr)}] 3 [4] 3 . Two plausible routes for the substitution and deprotonation are proposed using DFT calculations. However, considering the complexities involved, a better clarity of the Li/K divergence would require a more accurate modeling of the reaction species and explicit solvent molecules.

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Section: Methodsmentioning

confidence: 99%

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂

Goswami,

Sarkar,

Mallick

et al. 2024

Organometallics

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“…The next step involved the ortho-formylation of phenol 4. First attempts using SnCl 4 /paraformaldehyde [20] or hexamethylenetetramine [21,22] failed for this substrate. Next, we tried a procedure of Hofsløkken and Skattebøl, who described a convenient method for the ortho-formylation of phenols using MgCl 2 /Et 3 N and paraformaldehyde in dry MeCN [23].…”

Section: Total Synthesis Of Etm-204mentioning

confidence: 99%

Total synthesis of the isoquinolinium metabolite ETM-204 of Trabectidin

et al. 2021

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Ecteinascidin-743 (Trabectidin, Trabectedin®, Yondelis®) is a synthetically obtained pharmaceutical drug originally isolated from a marine tunicate. Trabectedin is used for the chemotherapy of soft-tissue sarcoma and ovarian cancer. The isoquinolinium metabolite ETM-204 has been found in biotransformation and degradation studies of Trabectedin. We report the first total synthesis of ETM-204 and its full spectroscopic characterization confirming the postulated structure. Central elements of the 12-step synthesis starting from 2-methyl-6-nitrophenol are a Cu-mediated conversion of an iodoarene to a phenol, a Skattebøl-formylation, and a modified Pomeranz–Fritsch cyclization to assemble the isoquinoline ring. The pH-dependence of its visual absorbance could be clarified. Graphic abstract

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Triazines, Tetrazines, and Fused Ring Polyaza Systems

Audebert

Clavier

Allain

2016

Progress in Heterocyclic Chemistry

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Synthesis and structural characterization of a highly substituted triazine ring comprising a sterically flexible methylene linker and coordinating substituents

Cited by 5 publications

References 132 publications

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂

Total synthesis of the isoquinolinium metabolite ETM-204 of Trabectidin

Triazines, Tetrazines, and Fused Ring Polyaza Systems

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Synthesis and structural characterization of a highly substituted triazine ring comprising a sterically flexible methylene linker and coordinating substituents

Cited by 5 publications

References 132 publications

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe3)2

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe3)2

Total synthesis of the isoquinolinium metabolite ETM-204 of Trabectidin

Triazines, Tetrazines, and Fused Ring Polyaza Systems

Contact Info

Product

Resources

About

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂

An Imidazolium Salt That Uncharacteristically Avoids the Imminent Deprotonation of Its Acidic 2-H Proton by KN(SiMe₃)₂