A ruthenium‐catalysed cross‐olefination of diazo compounds and sulfoxonium ylides is presented. Our reaction design exploits the intrinsic difference in reactivity of diazo compounds and sulfoxonium ylides as both carbene precursors and nucleophiles, which results in a highly selective reaction.

A simple and scalable method for stereoselective synthesis of thioethers directly from alcohols using isothiouronium salts is presented. The utility of this thiol-free reaction was exemplified by late-stage modification of complex molecules.

Organic synthesis boasts a wide array of reactions involving either radical species or ionic intermediates. The combination of radical and polar species, however, has not been explored to a comparable extent. Herein we present the hydrative aminoxylation of ynamides, a reaction which can proceed by either a polar‐radical crossover mechanism or through a rare cationic activation. Common to both processes is the versatility of the persistent radical TEMPO and its oxidised oxoammonium derivative TEMPO+. The unique mechanisms of these processes are elucidated experimentally and by in‐depth DFT‐calculations.

Abstract:The marine alkaloids (-)-lepadins A-C and (+)-lepadin D, belonging to two diastereoisomeric series, were synthesized from an (R)-phenylglycinol-derived tricyclic lactam via a common cisdecahydroquinoline intermediate. Crucial aspects of the synthesis are the stereochemical control in the assembly of the cisdecahydroquinoline platform, in the introduction of the C-2 methyl and C-3 hydroxy substituents, and in the generation of the C-5 stereocenter.

Stereoconvergent cyclocondensation reactions of (R)-or (S)-phenylglycinol with appropriately substituted cyclohexanone-based δ-keto esters are the key steps of short synthetic routes to enantiopure 5-, 7-, and 5,7-substituted cisdecahydroquinolines. The factors governing the stereoselectivity of the cyclocondensation are discussed. The potential of the methodology is illustrated by a protecting-group-free synthesis of the phlegmarine-type Lycopodium alkaloid (-)-cermizine B.