E/Z configuration determination of oximes and related derivatives through quantum mechanics NMR calculations. Scope and limitations of the leading probabilistic methods.

CORTÉS, I.; SAROTTI, A.M.*

ORGANIC & BIOMOLECULAR CHEMISTRY

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2023

1477-0520

Oximes and related derivatives featuring a C=N double bond are important in many areas of chemistry. Different methods for the determination of the E/Z configuration have been developed, each with its own scope and limitations. While some cannot be used when only one isomer is available, others require special NMR experiments. Here, three popular computational methodologies (DP4, DP4+, and ML-J-DP4) have been thoroughly studied using a challenging test set. Whereas DP4+ provides the best confidence, its computational cost might be high. On the other hand, ML-J-DP4 performs excellent in most cases at a fraction of CPU time. A detailed analysis of the structural factors affecting the NMR prediction and sense of the assignment is also provided.