Direct Synthesis of α-Fluoro-α-Triazol-1-yl Ketones from Sulfoxonium Ylides: A One-Pot Approach.

The work reported herein showcases a new route to access α-fluoro-α-triazol-1-yl ketones from sulfoxonium ylides via α-azido-α-fluoro ketone intermediates. In a one-pot, two-step sequence, the ketosulfoxonium reactant initially undergoes insertion of F and N, followed by a subsequent CuAAC reaction with arylacetylenes to install a 1,4-triazolo moiety. The approach allows for modification to both the sulfoxonium ylide and arylacetylene reactants.

Silver-Catalyzed 1,3-Acyloxy Migration/Diels-Alder Reaction of 1,9-Dien-4-yne Esters to Partially Hydrogenated Isoquinolines.

A synthetic method to prepare partially hydrogenated isoquinolines efficiently from silver-mediated [3,3]-sigmatropic rearrangement/Diels-Alder reaction of 1,9-dien-4-yne esters is described. The reactions were shown to be robust with a wide variety of substitution patterns tolerated to provide the corresponding nitrogen-containing heterocyclic products in good to excellent yields. This includes examples containing a bridgehead sp quaternary carbon center as well as the cycloisomerization of one substrate to give the corresponding bicyclic adduct in excellent yield at the gram scale.

Gold- and Brønsted Acid-Catalyzed Cycloisomerization of 1,8-Diynyl Vinyl Acetates to Bicyclo[2.2.1]hept-2-en-7-ones.

A synthetic method for the efficient assembly of bicyclo[2.2.1]hept-2-en-7-ones that relies on gold(I)-catalyzed Rautenstrauch rearrangement followed by Brønsted acid-mediated formal [3 + 2]-cycloaddition/deacetylation of 1,8-diynyl vinyl acetates at room temperature under atmospheric conditions is described.