Emotive ontology: extracting fine-grained emotions from terse, informal messages

A range of new biphenylazepinium salt organocatalysts effective for asymmetric epoxidation has been developed incorporating an additional substituted oxazolidine ring, and providing improved enantiocontrol in alkene epoxidation over the parent structure. Starting from enantiomerically pure amino-alcohols, tetracyclic iminium salts were obtained as single diastereoisomers through an atroposelective oxazolidine formation.