Highly stereoselective synthesis of trans-4-trifluoromethylsulfonyl-2,3-dihydrofurans from arsonium ylides and (E)-α-trifluoromethylsulfonyl-α,β-unsaturated ketones

Iron-catalyzed oxidative cyclization of olefinic 1,3-dicarbonyls with ketone C(sp3)–H bonds: facile access to 2,3-dihydrofurans

The reaction involves the addition of an α-carbonyl radical to the CC bond of olefinic 1,3-dicarbonyls followed by intramolecular 5-endo-trig cyclization.

Synthesis of Unsymmetrical Sulfides and Their Oxidation to Sulfones to Discover Potent Antileishmanial Agents

Unsymmetrical sulfides were first synthesized using combinations of a 1,3-dicarbonyl, an aromatic aldehyde and a thiol in the presence of 10 mol % ethanolic piperidine. These sulfides derivatives were subsequently converted into corresponding sulfones via oxidation in the presence of m-chloroperoxybenzoic acid (m-CPBA) at ice-bath to room temperature. The former reaction was achieved at room temperature through one-pot three-component. The later was obtained in good yields using mild reaction conditions with flexibility in choice from a range of substrates. The antimicrobial properties of the newly synthesized sulfone derivatives were investigated against the protozoan parasite, Leishmania donovani, a causative agent of visceral leishmaniasis (VL). Nine sulfone derivatives were found to be efficacious and exhibited significant antimicrobial activity. Further, these compounds were nontoxic on murine peritoneal macrophages thus eliminating potential cytoxicity in the host cells. These compounds may be indicated as potential leads in the treatment of visceral leishmaniasis.

One-Pot Synthesis of Allylic Sulfones, Ketosulfones, and Triflyl Allylic Alcohols from Domino Reactions of Allylic Alcohols with Sulfinic Acid under Metal-Free Conditions

A metal-free tandem procedure by using a sulfonylation reaction of aryl allylic alcohols followed by an iodobenzenediacetate (PIDA)-promoted oxidative functionalization has been established. Allylic sulfones, γ-ketosulfones, and triflyl allylic alcohols have been constructed in a single operation. The methodology incorporates the sulfonyl (both aryl and triflyl) functionality with a simple work-up procedure.

Iron-catalyzed tandem cyclization of olefinic dicarbonyl compounds with benzylic Csp3–H bonds for the synthesis of dihydrofurans

A novel iron-catalyzed radical cyclization of olefinic dicarbonyl compounds with benzyl hydrocarbons and simple alkanes has been developed. This protocol provides ready access to a variety of dihydrofurans containing a quaternary carbon center in moderate to good yields.

Regioselective access to CF3S-substituted dihydrofurans from homopropargylic alcohols with trifluoromethanesulfenamide

A facile access to 4-((trifluoromethyl)thio)-2,3-dihydrofurans from unprotected homopropargylic alcohols in high regioselectivity is reported.