Study of heavy atom influence on poly-halogenated compounds using DP4/MM-DP4+/DP4+: insights and trends.

Nuclear magnetic resonance (NMR) spectroscopy complemented by density functional theory (DFT) calculations is a crucial tool for structural elucidation. Nevertheless, the precision of NMR predictions is influenced by the 'heavy atom effect', wherein heavy atoms affect the shielding values of neighboring light atoms (HALA effect). Standard practice in the field involves removing the conflicting signals.

Breaking the DFT Energy Bias Caused by Intramolecular Hydrogen-Bonding Interactions with MESSI, A Structural Elucidation Method Inspired by Wisdom of Crowd Theory.

The use of quantum-based NMR methods to complement and guide the connectivity and stereochemical assignment of natural and unnatural products has grown enormously. One of the unsolved problems is related to the improper calculation of the conformational landscape of flexible molecules that have functional groups capable of generating a complex network of intramolecular H-bonding (IHB) interactions. Here the authors present MESSI (Multi-Ensemble Strategy for Structural Identification), a method inspired by the wisdom of the crowd theory that breaks with the traditional mono-ensemble approach.

Acid-Promoted Iso-Nazarov Cyclization of Conjugated -Dienones and Dienals for the Synthesis of 2-Cyclopentenones.

The acid-promoted cyclization of all- linearly conjugated dienones and dienals constitutes a synthetic strategy for the construction of 2-cyclopentenones.