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1. 17 O NMR and 15 N NMR chemical shifts of sterically-hindered amides: ground-state destabilization in amide electrophilicity

   https://doi.org/10.1039/c9cc01402k  

   Pace, Vittorio ; Holzer, Wolfgang ; Ielo, Laura ; Shi, Shicheng ; Meng, Guangrong ; Hanna, Mina ; Szostak, Roman ; Szostak, Michal ( April 2019 , Chemical Communications)

   The structure and spectroscopic properties of the amide bond are a topic of fundamental interest in chemistry and biology. Herein, we report 17 O NMR and 15 N NMR spectroscopic data for four series of sterically-hindered acyclic amides. Despite the utility of 17 O NMR and 15 N NMR spectroscopy, these methods are severely underutilized in the experimental determination of electronic properties of the amide bond. The data demonstrate that a combined use of 17 O NMR and 15 N NMR serves as a powerful tool in assessing electronic effects of the amide bond substitution as a measure of electrophilicity of the amide bond. Notably, we demonstrate that steric destabilization of the amide bond results in electronically-activated amides that are comparable in terms of electrophilicity to acyl fluorides and carboxylic acid anhydrides. 

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2. N -Methylamino Pyrimidyl Amides (MAPA): Highly Reactive, Electronically-Activated Amides in Catalytic N–C(O) Cleavage

   https://doi.org/10.1021/acs.orglett.7b02288  

   Meng, Guangrong ; Lalancette, Roger ; Szostak, Roman ; Szostak, Michal ( August 2017 , Organic Letters)
3. Complexity-Building Photoinduced Cascade Involving C sp2 –C sp3 Coupling of Aromatic Amides via [2 + 2] Reactivity of ESIPT-Generated o- Azaxylylenes

   https://doi.org/10.1021/acs.orglett.3c00092  

   Reddy, D. Sai ; Novitskiy, Ivan M. ; Kutateladze, Andrei G. ( February 2023 , Organic Letters)
4. Thioesterification and Selenoesterification of Amides via Selective N–C Cleavage at Room Temperature: N–C(O) to S/Se–C(O) Interconversion

   https://doi.org/10.1055/s-0039-1690055  

   Rahman, Md. Mahbubur ; Li, Guangchen ; Szostak, Michal ( March 2020 , Synthesis)

   The direct nucleophilic addition to amides represents an attractive methodology in organic synthesis that tackles amidic resonance by ground-state destabilization. This approach has been recently accomplished with carbon, nitrogen and oxygen nucleophiles. Herein, we report an exceedingly mild method for the direct thioesterification and selenoesterification of amides by selective N–C(O) bond cleavage in the absence of transition metals. Acyclic amides undergo N–C(O) to S/Se–C(O) interconversion to give the corresponding thioesters and selenoesters in excellent yields at room temperature via a tetrahedral intermediate pathway (cf. an acyl metal). 

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5. Synthesis and Characterization of Non-Aqueous [Tc X M-PW 11 O 39 ] n - with M = O, N: Comparing Tc V and Tc VI in Metal Oxide Matrices: Synthesis and Characterization of Non-Aqueous [Tc X M-PW 11 O 39 ] n - with M = O, N: Comparing Tc V and Tc VI in Metal Oxide Matrices

   https://doi.org/10.1002/ejic.201900864  

   Burton-Pye, Benjamin P. ; Dembowski, Mateusz ; Lukens, Jr., Wayne W. ; Cruz, Anthony ; Althour, Alrasheed ; Lopez, Gustavo E. ; Salcedo, Ramsey ; Gallagher, Colleen M. B. ; McGregor, Donna ; Francesconi, Lynn C. ( November 2019 , European Journal of Inorganic Chemistry)