N-p-Toluenesulfinylimidazole: A New in situ Reagent for the Mild and Efficient Synthesis of p-Toluenesulfinate Alkyl Esters and Aryl Esters
作者:Shawn R. Hitchcock、Jessica L. Shaw、Brad J. Austermuehle、Jordan M. Witte、Timothy R. Dorsey、Christina Delach、Christopher G. Hamaker
DOI:10.1055/a-1472-7578
日期:2021.8
A new synthetic methodology has been developed for the synthesis of sulfinate alkyl and aryl esters. The methodology involves the combination of p-toluenesulfinic acid and 1,1′-carbonyldiimidazole (CDI) to create the putative reagent sulfinylimidazole. The process spontaneously releases carbon dioxide upon the addition of the CDI to the acid suggesting the rapid formation of the proposed reagent. Reaction
Metal-Free Electrophilic Alkynylation of Sulfenate Anions with Ethynylbenziodoxolone Reagents
作者:Stephanie G. E. Amos、Stefano Nicolai、Alec Gagnebin、Franck Le Vaillant、Jerome Waser
DOI:10.1021/acs.joc.9b00050
日期:2019.3.15
Alkynyl sulfoxides are important buildingblocks with a unique reactivity in organic chemistry, but only a few reliable methods have been reported to synthesize them. A novel route to access alkynyl sulfoxides is reported herein by using ethynyl benziodoxolone (EBX) reagents to trap sulfenate anions generated in situ, via a retro-Michael reaction. The reaction takes place under metal-free and mild
One-pot syntheses of sulfinates, sulfinamides, and thiosulfinates by O-, N-, and S-sulfinylations of alcohols, amines, and thiols with p-toluenesulfinic acid in the presence of various activating reagents, phenyl phosphorodichloridate (1), diphenyl phosphoro-chloridate (2), triphenylphosphine N-chlorosuccinimide (NCS) (3), and 3-(phthalimidoxy)-1, 2-benzoisothiazole 1, 1-dioxide (4), were investigated. All of these reagents were reasonably effective for O-and S-sulfinylation, but ineffective for N-sulfinylation. Among them, the reagents 1 and 2 were slightly more efficient than the others.
Reaction of alcohols with sodium arenesulfinates could afford either sulfones or sulfinates, and O‐attack of sulfinate anions onto in situ generated carbocation intermediates from alcohols was the previous proposed mechanism in many syntheses of sulfinates. This concept, which is often used consciously or unconsciously, was revised herein by using isotopic labeling experiments and development of an
A Mitsunobu approach for the synthesis of sulfinate esters by direct nucleophilic substitution of alcohols is described. The salient features of this strategy include neutral and metal‐free conditions for the rapid synthesis of sulfinates in high yields. The present protocol using p‐toluenesulfonylmethyl isocyanide (TosMIC) and the triphenylphosphine (TPP)/diisopropyl azodicarboxylate (DIAD) reagent