Intermolecular Acyl-Transfer Reactions in Molecular Crystals

Area of Science:

• Solid-state chemistry
• Organic synthesis
• Crystallography

Background:

• Predicting organic compound reactions in the solid state is challenging due to limited data compared to solution-state chemistry.
• The discovery of intermolecular acyl transfer in molecular crystals of racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoformate (DiBz) sparked further investigation.
• Understanding solid-state reactivity is crucial for developing novel synthetic methods and materials.

Purpose of the Study:

• To systematically investigate the structure-reactivity correlations of molecular crystals for acyl transfer reactions.
• To identify essential conditions and noncovalent interactions governing solid-state acyl transfer.
• To predict and control acyl transfer reactivity in diverse molecular crystals.

Main Methods:

• Synthesis and structural analysis of DiBz analogues with varying crystal structures.
• Investigation of polymorphism, cocrystallization, and reactivity of the synthesized compounds.
• Utilized X-ray diffraction data and the Cambridge Structural Database (CSD) for structure-reactivity correlation.

Main Results:

• Identified three critical conditions for intermolecular acyl transfer: favorable geometry, specific noncovalent interactions (C-H···π), and lattice channels.
• Demonstrated that polymorphs and cocrystals exhibit different reactivities due to variations in molecular conformation and arrangement.
• Successfully predicted acyl transfer reactivity in new molecular crystals based on supramolecular structure-reactivity correlations.

Conclusions:

• Established a framework for understanding and predicting acyl transfer reactions in molecular crystals.
• Highlighted the potential of solid-state reactions for unique product selectivity and sustainable green chemistry.
• Opened new avenues for research in organic solid-state reactions with potential applications in synthesis, materials science, and industry.