Even moderately nucleophilic dienes react with simple aldehydes in the presence of a new Cr(III) catalyst in a hetero-Diels-Alder reaction [Eq. (1)]. Tetrahydropyranyl products with up to three stereogenic centers are generated in near-perfect diastereoselectivities and with greater than 90 % ee (99 % ee for the example shown). TBAF=tetrabutylammonium fluoride; TBS=tert-butyldimethylsilyl; TES=triethylsilyl.

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The first large scale analysis of in vitro absorption, distribution, metabolism, excretion, and toxicity (ADMET) data shared across multiple major pharma has been performed. Using advanced matched molecular pair analysis (MMPA), we combined data from three pharmaceutical companies and generated ADMET rules, avoiding the need to disclose the full chemical structures. On top of the very large exchange of knowledge, all companies involved synergistically gained approximately 20% more rules from the shared transformations. There is good quantitative agreement between the rules based on shared data compared to both individual companies' rules and rules published in the literature. Known correlations between log  D, solubility, in vitro clearance, and plasma protein binding also hold in transformation space, but there are also interesting exceptions. Data pools such as this allow focusing on particular functional groups and characterizing their ADMET profile. Finally the role of a corpus of robustly tested medicinal chemistry knowledge in the training of medicinal chemistry is discussed.

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