The effect of substituents on the rate of conrotatory thermal cleavage of aziridine has been studied at the MP2(Full)/6-311++G(d,p)//MP2(Full)/6-31+G(d) level and also using SCS-MP2 methodology. While the parent compound has a high free energy of activation (194.6 kJ mol(-1)), this value could be drastically lowered by substituent effects. Anionic species were found to be particularly effective in increasing the calculated reaction rate. The potential utility of this approach in 1,3-dipolar cycloaddition is discussed.

Download full-text PDF

Source
http://dx.doi.org/10.1039/c1ob05588gDOI Listing

Publication Analysis

Top Keywords

substituent effects
8
effects rate
4
rate formation
4
formation azomethine
4
azomethine ylides
4
ylides computational
4
computational investigation
4
investigation substituents
4
substituents rate
4
rate conrotatory
4

Similar Publications

Base-Promoted [4 + 1 + 1] Multicomponent Tandem Cycloaddition of -Substituted Nitroarenes, Aldehydes, and Ammonium Salts To Access 2,4-Substituted Quinazoline Frameworks.

J Org Chem

January 2025

Key Laboratory of Biomass Green Chemical Conversion of Yunnan Provincial Education Department, Yunnan Key La-boratory of Chiral Functional Substance Research and Application, School of Chemistry & Environment, Yunnan Minzu University, Kunming 650504, P. R. China.

We report a base-promoted, metal-free multicomponent tandem reaction, involving a [4 + 1 + 1] cycloaddition process between -substituted nitroarenes, aldehydes, and ammonium salts. Modifying the substituents on the nitroaromatic compounds effectively provides structurally diverse 2-substituted and 4-alkenylquinazolines with good to excellent yields (77%-90% and quinazoline 51 examples) and high tolerance for various inorganic ammonium salts (13 examples, such as NH·HO, NHCl, and NHHF). A new method for constructing 2,4-substituted quinazoline compounds with high selectivity from simple nitrogen source compounds was developed, and the reaction can be scaled up to a gram scale.

View Article and Find Full Text PDF

Chemical structure-biological activity of 1,4-naphthoquinone analogs as potential Aedes aegypti larvicides.

Pest Manag Sci

January 2025

Department of BioMolecular Sciences and the Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, USA.

Background: 1,4-Naphthoquinone compounds have shown pesticidal activity against Aedes aegypti larvae, a key vector of diseases such as dengue and Zika. However, limited knowledge of their structure-activity relationships has hindered their optimization for pesticide development. This study investigates the structure-activity relationships of 1,4-naphthoquinone, particularly 2-hydroxy-1,4-naphthoquinone and its derivatives.

View Article and Find Full Text PDF

Xylan thermoplastics with closed-loop recyclability.

Carbohydr Polym

March 2025

Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Efficient Production of Forest Resources, Beijing Forestry University, Beijing 100083, China. Electronic address:

Xylan-derived packaging materials have gained considerable popularity owing to their renewability, non-toxicity, and biodegradability. However, thermoforming is challenging owing to its rigid structure and hydrogen-bonding network of the xylan molecular chain, which limits its large-scale production. Herein, a heat-processable xylan derivative, xylan cinnamate (XC), was synthesized via an esterification reaction in ionic liquids.

View Article and Find Full Text PDF

Exploring Singlet Carbyne Anions and Related Low-Valent Carbon Species Utilizing a Cyclic Phosphino Substituent.

Acc Chem Res

January 2025

Department of Chemistry and Research Center for Chemical Biology and Omics Analysis, College of Science, Southern University of Science and Technology, Shenzhen 518055, China.

ConspectusThe advancement of synthetic methodologies is fundamentally driven by a deeper understanding of the structure-reactivity relationships of reactive key intermediates. Carbyne anions are compounds featuring a monovalent anionic carbon possessing four nonbonding valence electrons, which were historically confined to theoretical constructs or observed solely within the environment of gas-phase studies. These species possess potential for applications across diverse domains of synthetic chemistry and ancillary fields.

View Article and Find Full Text PDF

Discovery of thymoquinone analogues with high anthelmintic activity against monogenean infections in goldfish (Carassius auratus).

Vet Parasitol

January 2025

College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; National Aquatic Animal Diseases Para-reference laboratory (HZAU), Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan 430070, China; Hubei Engineering Technology Research Center for Aquatic Animal Diseases Control and Prevention, Wuhan 430070, China. Electronic address:

Monogenean parasites are harmful pathogens in aquaculture systems. Current treatment strategies for monogenean infections are unsatisfactory, making the discovery of new drugs urgent. Thymoquinone (TQ), a natural monoterpene isolated from Nigella sativa L.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!