Understanding Bio-Orthogonal Strain-Driven Sydnone Cycloadditions: Data-Assisted Profiles and the Search for Linear...

Area of Science:

• Organic Chemistry
• Bioorthogonal Chemistry
• Computational Chemistry

Background:

• Metal-free [3+2] cycloadditions involving mesoionic rings and strained cycloalkynes are increasingly important for bioorthogonal chemistry.
• Despite extensive research, the precise structural and stereoelectronic factors governing these reactions remain incompletely understood.
• Data-driven approaches, including machine learning, offer new avenues for quantitative analysis of these transformations.

Purpose of the Study:

• To investigate the structure-reactivity relationships in metal-free [3+2] cycloadditions.
• To identify and quantify the influence of electronic and strain-release effects on reaction rates.
• To explore the potential of these cycloadditions as probes for delocalization-assisted strain release.

Main Methods:

• Utilized computational simulations and machine learning for quantitative estimations.
• Performed Hammett-type correlation analyses on phenylsydnone derivatives reacting with bicyclo[6.1.0]nonyne carbinol.
• Accurately estimated activation barriers and predicted rate constants.

Main Results:

• Unveiled a series of linear relationships, including Hammett-type correlations, between structure and reactivity.
• Identified deviations from linearity, highlighting complex interplay of factors.
• Demonstrated the significance of integrating strain release and electronic effects in predicting organic reactivity.

Conclusions:

• The study provides a deeper understanding of the factors governing mesoionic cycloadditions.
• Findings emphasize the importance of considering both strain release and electronic effects for reaction optimization.
• Results suggest potential applications of these cycloadditions in measuring strain release phenomena in related chemical systems.