<i>α</i>-Sulfenyl-Directed Ring-Opening Reactions of Epoxides. 1. Highly Regio- and Stereoselective Reaction with Organo-Aluminum Reagents and Application to the Synthesis of an Aggregation Pheromone
rearrangement of the sulfenyl group to the C-2 with the complete inversion of the configuration at the C-2. The reactions of these epoxides were considered to proceed via an episulfonium ion intermediate. Upon applying the present reaction, an aggregation pheromone of African Palm Weevil was stereoselectively synthesized in short steps.
Catalytic Asymmetric Thiofunctionalization of Unactivated Alkenes
作者:Scott E. Denmark、David J. P. Kornfilt、Thomas Vogler
DOI:10.1021/ja2064395
日期:2011.10.5
Catalytic asymmetric sulfenylation of double bonds has been achieved using a BINAM-based phosphoramide catalyst and an electrophilic sulfur source. Simple alkenes as well as styrenes afforded sulfenylated tetrahydrofurans and tetrahydropyrans by closure with pendant hydroxyl or carboxyl groups. Intermolecular thiofunctionalizations were also achieved with simple alcohols or carboxylic acids as the nucleophiles.
Synthesis and Reactivity of Enantiomerically Enriched Thiiranium Ions
作者:Scott E. Denmark、Thomas Vogler
DOI:10.1002/chem.200901377
日期:2009.11.2
Enantiomericallyenrichedthiiraniumion 5 has been prepared by silver‐assisted ionization of chloro sulfide 4 at −20 °C. This thiiraniumion is configurationally stable in solution up to room temperature as demonstrated by the stereospecific capture of the ion by various oxygen‐ and nitrogen‐based nucleophiles. Both isolated olefins and weak Lewis bases can promote the racemization of 5 but these