Acid-Promoted Carbosulfenylation of 1,6-Dienes: Selective Synthesis of Dehydropiperidines Scaffolds.

An efficient method for the acid-catalyzed carbosulfenylation of 1,6-diene has been achieved employing -(aryl/alkylthio)succinimides as a thiolating reagent. The reaction involves the generation of an episulfonium ion followed by intramolecular trapping with alkenes, which offers access to diverse thiolated dehydropiperidines in good yield. In addition, the synthesis of dihydropyran and cyclohexene derivatives, as well as the conversion of the arylthiol moiety to useful functional groups, were also demonstrated.

Catalytic enantioselective oxysulfenylation of -vinylanilides.

TfNH-assisted BINAM-derived thiophosphoramide catalysis has been accomplished for the enantioselective oxysulfenylation of -vinylanilides with -(aryl/alkylthio)imides. The developed reaction offers access to diverse substituted aryl/alkylthio tethered 3,1-benzoxazines in excellent yields and enantiomeric ratios. Furthermore, synthetic applications of benzoxazines and aryl/alkylthio moieties and a transition state model for the observed enantioselectivity are also discussed.

Cp*Co(III)-catalyzed C2-thiolation and C2,C3-dithiolation of substituted indoles with -(arylthio)succinimide.

A general and efficient Cp*Co-catalyzed C2-thiolation and C2,C3-dithiolation of indole derivatives has been achieved employing -(aryl/alkylthio)succinimide as a thiolating reagent. This external oxidant-free method utilizes only catalytic amounts of additive and tolerates various functional groups to afford various thiolated products in good yields. Control experiments revealed the importance of the Cp*Co-catalyst for both C2- and C3-thiolation.