D iCE: Diastereomeric in Silico Chiral Elucidation, Expanded DP4 Probability Theory Method for Diastereomer and...

Area of Science:

• Computational Chemistry
• Organic Chemistry
• Spectroscopy

Background:

• Nuclear Magnetic Resonance (NMR) spectroscopy is crucial for molecular structure determination.
• Predicting NMR chemical shifts aids in assigning stereochemistry and regiochemistry.
• Existing methods may have limitations in accuracy or computational efficiency.

Purpose of the Study:

• To develop a highly accurate probability theory algorithm for NMR chemical shift prediction.
• To determine stereochemistry of diastereomers and regiochemistry using computational methods.
• To create an efficient tool for structural assignment in organic chemistry.

Main Methods:

• Density Functional Theory (DFT) GIAO calculations at the B3LYP/cc-pVDZ level.
• Geometry optimization and CPCM solvent model for conformer calculations.
• Development of the D iCE algorithm based on DP4, utilizing Boltzmann-averaged shielding constants for 1H, 13C, and 15N NMR.

Main Results:

• High accuracy in predicting NMR chemical shifts for 1H, 13C, and 15N.
• Successful determination of stereochemistry and regiochemistry.
• Chemical shift calculation errors fitted to Student's t-distribution (1H, 13C) and normal distribution (15N).

Conclusions:

• The D iCE algorithm provides a computationally inexpensive and highly accurate method for structural assignment.
• This approach enhances the utility of NMR spectroscopy in complex molecule analysis.
• The algorithm is applicable across various solvents and nuclei (1H, 13C, 15N).