Design for Energy Efficiency

Sáenz‐Galindo, Aidé; Cedillo-Portilo, José Juan; Espinoza-Cavazos, Karina G.; León-Martínez, P. A. De; Castañeda-Facio, Adali O.

doi:10.1201/9780429291166-7

Cited by 3 publications

(4 citation statements)

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“…[41] Our method not only simplifies the synthesis by reducing the number of reaction steps from 4 to 3, but also improves atom economy (more than two-fold, when using K 2 CO 3 as base) by utilizing the intrinsic reactivity of the Nms group for carboxylate activation. [42] This eliminates the necessity for a deprotection agent (TFA) and coupling reagents (EDC and HOBt), only requiring acid and baseboth reagents essential for amide coupling in any case.…”

Section: Methodsmentioning

confidence: 99%

“…Previous attempts to synthesize 16 a required a Boc group to prepare 14 b , which had to be cleaved prior to amide coupling and required isolation of the intermediate amine (by extraction→a total of 2 steps with 2 pots) [41] . Our method not only simplifies the synthesis by reducing the number of reaction steps from 4 to 3, but also improves atom economy (more than two‐fold, when using K 2 CO 3 as base) by utilizing the intrinsic reactivity of the Nms group for carboxylate activation [42] . This eliminates the necessity for a deprotection agent (TFA) and coupling reagents (EDC and HOBt), only requiring acid and base—both reagents essential for amide coupling in any case.…”

Section: Methodsmentioning

confidence: 99%

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Deprotective Functionalization: A Direct Conversion of Nms‐Amides to Carboxamides Using Carboxylic Acids

Spieß,

Brześkiewicz,

Meyrelles

et al. 2024

Angew Chem Int Ed

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The nature of protecting group chemistry necessitates a deprotection step to restore the initially blocked functionality prior to further transformation. As this aspect of protecting group manipulation inevitably adds to the step count of any synthetic sequence, the development of methods enabling simultaneous deprotection and functionalization (“deprotective functionalization”—distinct from “deprotection followed by functionalization”) is appealing, as it has the potential to improve efficiency and streamline synthetic routes. Herein, we report a deprotective functionalization of the newly introduced Nms‐amides guided by density functional theory (DFT) analysis, which exploits the inherent Nms reactivity. Mechanistic studies further substantiate and help rationalize the exquisite reactivity of Nms‐amides, as other commonly used protecting groups are shown not to exhibit the same reactivity patterns. The practicality of this approach was ultimately demonstrated in selected case studies.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Deprotective Functionalization: A Direct Conversion of Nms‐Amides to Carboxamides Using Carboxylic Acids

Spieß,

Brześkiewicz,

Meyrelles

et al. 2024

Angew Chem Int Ed

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“…Diese musste vor der Amidkupplung gespalten werden, was wiederum die Isolierung des Amin‐Zwischenprodukts erforderte (durch Extraktion – insgesamt 2 Schritte mit 2 Reaktionsgefäßen) [41] . Unsere Methode vereinfacht nicht nur die Synthese, indem sie die Anzahl der Reaktionsschritte von 4 auf 3 reduziert, sondern verbessert auch die Atomökonomie (mehr als das Zweifache, wenn K 2 CO 3 als Base verwendet wird), indem sie die intrinsische Reaktivität der Nms‐Gruppe für die Carboxylat‐Aktivierung nutzt [42] . Dadurch entfällt die Notwendigkeit der Verwendung eines Entschützungsreagenzes (TFA) und von Amid‐Kupplungsreagenzien (EDC und HOBt), so dass nur noch Säure und Base benötigt werden ‐ beides Reagenzien, die für die Amidkupplung in jedem Fall erforderlich sind.…”

Section: Methodsunclassified

Entschützende Funktionalisierung: eine direkte Umwandlung von Nms‐Amiden in Carbonsäureamide

Spieß,

Brześkiewicz,

Meyrelles

et al. 2024

Angewandte Chemie

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Klassische Schutzgruppenchemie erfordert unweigerlich einen Entschützungsschritt, um die ursprünglich blockierte Funktionalität vor weiteren Umwandlungen wiederherzustellen. Da dieser Aspekt der Schutzgruppenmanipulation zwangsläufig die Anzahl der Schritte jeder Synthesesequenz erhöht, bieten Methoden, die eine gleichzeitige Entschützung und Funktionalisierung ermöglichen („entschützende Funktionalisierung“, im Gegensatz zur Entschützung mit anschließender Funktionalisierung), attraktive Vorteile, um die Effizienz zu steigern und synthetische Routen zu verkürzen. In diesem Bericht präsentieren wir eine Methode zur entschützenden Funktionalisierung der neu eingeführten Nms‐Amide, die auf einer Analyse mittels Dichtefunktionaltheorie (DFT) basiert und die inhärente Nms‐Reaktivität ausnutzt. Mechanistische Studien erklären außerdem warum andere häufig verwendete Schutzgruppen nicht die gleichen Reaktivitätsmuster aufweisen. Die Anwendbarkeit dieses Ansatzes wurde anhand zahlreicher Substrate demonstriert und schließlich verwendet, um Arzneimittelderivate effizienter und mit verkürzten Synthesewegen herzustellen.

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“…The concept of atom economy can be used to define new pollution prevention benchmarks and can be applied to any synthesis as it measures the greenness of the chemical reaction. 23 The significant FTIR data of H 2 AD1Me, [Pd(AD1Me)], and [Ni(AD1Me)] are listed in Table 6. The IR spectrum of the ligand H 2 AD1Me exhibited a strong band at 1636 cm −1 assignable to the azomethine ν(C�N) group.…”

Section: Physicochemical and Spectroscopic Characterizationmentioning

confidence: 99%

Synthesis, Structural Characterization, Hirshfeld Surface Analysis, and Antibacterial Study of Pd(II) and Ni(II) Schiff Base Complexes Derived from Aliphatic Diamine

et al. 2022

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A Schiff base bearing two methyl substituents, namely, 6,6′-((1E,1′E)-((2,2-dimethylpropane-1,3-diyl) bis(azanylylidene)) bis(methanylylidene)) bis(2-methylphenol) [H2AD1Me] was synthesized and characterized through physicochemical and spectroscopic analyses. Then, the Schiff base was complexed with Pd(II) and Ni(II) to form [Pd(AD1Me)] and [Ni(AD1Me)], respectively. Both metal complexes were successfully obtained and characterized through several analyses, viz., melting point, elemental analysis, molar conductivity, magnetic susceptibility, FTIR, 1H NMR, UV–vis, and single crystal X-ray diffraction. A quantitative analysis of the intermolecular interactions in the crystal structures has been performed using Hirshfeld surface analysis. Both metal complexes were crystallized in a monoclinic crystal system with the space group of P21/c. Additionally, the deprotonated phenolic oxygen atom (O1/O2) and azomethine nitrogen atom (N1/N2) of the ligand chelate the Pd(II) and Ni(II) ions, forming a slightly distorted square-planar complex containing three six-membered rings encircling the metal core with dsp2 hybridization. The shift of ν(CN) to a higher frequency in FTIR by 26–28 cm–1 indicated that the complexation to Pd(II) and Ni(II) through the azomethine N was established. It was further supported through the shifting of the azomethine proton signal to higher or lower chemical shifts with Δδ = 0.43–1.15 ppm in 1H NMR. In addition, the shifting of the n−π*(CN) band in UV–vis spectra with Δλ = 24–40 nm indicated the involvement of azomethine nitrogen in the complexation. All the compounds showed no significant antibacterial activity against three bacterial strains, namely, Staphylococcus aureus subsp. aureus Rosenbach (ATCC 6538), Streptococcus mutans Clarke (ATCC 700,610), and Proteus vulgaris (ATCC 6380), as the percent growth inhibition calculated was less than 90%.

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Design for Energy Efficiency

Cited by 3 publications

References 1 publication

Deprotective Functionalization: A Direct Conversion of Nms‐Amides to Carboxamides Using Carboxylic Acids

Deprotective Functionalization: A Direct Conversion of Nms‐Amides to Carboxamides Using Carboxylic Acids

Entschützende Funktionalisierung: eine direkte Umwandlung von Nms‐Amiden in Carbonsäureamide

Synthesis, Structural Characterization, Hirshfeld Surface Analysis, and Antibacterial Study of Pd(II) and Ni(II) Schiff Base Complexes Derived from Aliphatic Diamine

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