Chiral Brønsted acid catalyzed asymmetric oxidation of N-acyl sulfenamide by H2 O2 : An efficient approach to obtaining chiral N-acyl sulfinamide

Synthesis of N-Acylsulfenamides from (Hetero)Aryl Iodides and Boronic Acids by One-Pot Sulfur-Arylation and Dealkylation

A general one-pot approach to diverse N-acylsulfenamides from a common S-phenethylsulfenamide starting material is reported. This approach was demonstrated by C-S bond formation utilizing commercially abundant (hetero)aryl iodides and boronic acids to provide sulfilimine intermediates that undergo thermal elimination of styrene. In contrast, all prior approaches to N-acylsulfenamides rely on thiol inputs to introduce sulfenamide S-substituents. A broad scope of reaction inputs was demonstrated including for approved drugs and drug precursors with dense display of functionality. Several different types of sulfur functionalization were performed on a sulfenamide derived from a complex precursor of the blockbuster anticoagulant drug apixaban, highlighting the utility of this approach for the introduction of high oxidation state sulfur groups in complex bioactive compounds. Mechanistic studies established that the key styrene elimination step proceeds by a concerted elimination that does not require reagents or catalysts, and therefore, this one-pot approach should be applicable to the synthesis of N-acylsulfenamides utilizing diverse electrophiles and reaction conditions for C-S bond formation.

Nickel-Catalyzed Enantioselective Synthesis of Dienyl Sulfoxide

Sulfoxides are widely used in the pharmaceutical industry and as ligands in asymmetric catalysis. However, the efficient asymmetric synthesis of this structural motif remains limited. In this study, we disclosed a Ni-catalyzed enantioconvergent reaction that utilizes both racemic allenyl carbonates and β-sulfinyl esters. Our method employs cheap and more sustainable Ni(II) as a precatalyst and successfully overcomes the challenging poisoning effect and instability of sulfenate generated in situ. This enables the synthesis of a series of dienyl sulfoxides with enantioselectivity of up to 98 % ee. The product exhibits tremendous potential in various applications, including diastereoselective Diels-Alder reactions, coordination with transition metals, and incorporation into medicinal compounds, among others. Using a combination of experimental and computational methods, we have uncovered an interesting associated outersphere mechanism that contrasts with conventional mechanisms commonly observed in asymmetric transition metal catalysis.

Constructing N-Acyl/N-Sulfonyl Aza-Sulfur Derivatives from Amides/Sulfonamides and Thiophthalimides via Oxidant Regulation

Here, we have constructed five distinct types of N-acyl or N-sulfonyl aza-sulfur scaffolds using readily available (sulfon)amides and thiophthalimides with precise regulation of oxidants. Our novel methods feature one-pot mild reaction conditions and simple operation, thereby making them highly convenient for the late-stage diversification of various amide drugs, bioactive molecules, and peptides.

Synthesis of N-Acylsulfenamides from Amides and N-Thiosuccinimides

Herein is reported a robust and general method for the preparation of N-acylsulfenamides, important functionalities that have recently been utilized as central inputs for the asymmetric synthesis of high oxidation state sulfur compounds. This straightforward transformation proceeds by reaction of primary amides, carbamates, sulfonamides, sulfinamides, and ureas with stable N-thiosuccinimides or N-thiophthalimides, which in turn are prepared in a single step from commercial thiols. The use of stable N-thiosuccinimide and N-thiophthalimide reactants is desirable because it obviates the use of highly reactive sulfenyl chlorides.