33117-71-4

Upstream product

• 16174-75-7 2-[2-(p-tolylsulfanyl)phenyl]acetic acid 
• 19202-12-1 1-(3,4-dihydroquinolin-1(2H)-yl)-2-phenylethan-1-one 
• 103-82-2 phenylacetic acid 
• 635-46-1 1,2,3,4-tetrahydroisoquinoline 
• 18698-96-9 o-iodophenylacetic acid 
• 172470-08-5 1-(2-p-Tolylsulfanyl-phenyl)-5,6-dihydro-1H,4H-pyrrolo[3,2,1-ij]quinolin-2-one 
• 207349-81-3 1-(3,4-Dihydro-2H-quinolin-1-yl)-2-(2-p-tolylsulfanyl-phenyl)-ethanone 
• 172470-12-1 1-(3,4-Dihydro-2H-quinolin-1-yl)-2-[2-(toluene-4-sulfinyl)-phenyl]-ethanone 

Relevant academic research and scientific papers

Metal-Free Formal Oxidative C?C Coupling by In Situ Generation of an Enolonium Species

Much contemporary organic synthesis relies on transformations that are driven by the intrinsic, so-called “natural”, polarity of chemical bonds and reactive centers. The design of unconventionally polarized synthons is a highly desirable strategy, as it generally enables unprecedented retrosynthetic disconnections for the synthesis of complex substances. Whereas the umpolung of carbonyl centers is a well-known strategy, polarity reversal at the α-position of a carbonyl group is much rarer. Herein, we report the design of a novel electrophilic enolonium species and its application in efficient and chemoselective, metal-free oxidative C?C coupling.

Additive and Vinylogous Pummerer Reactions of Amido Sulfoxides and Their Use in the Preparation of Nitrogen Containing Heterocycles

The α-thiocarbocation generated from the Pummerer reaction of N-methyl-N-phenyl-2-[2-(toluene-4-sulfinyl)phenyl]acetamide undergoes Friedel-Crafts reaction at the γ-carbon with the tethered aromatic ring. Reductive removal of the phenylthio group from the resulting product using Raney nickel occurs in high yield, and the overall reaction represents a new method for the synthesis of a variety of 3-phenyl-substituted oxindoles. Treatment of the related N-benzyl-N-alkyl amido sulfoxide system with trifluoroacetic anhydride affords tetrahydroisoquinolone derivatives. The product distribution encountered coincides with the rotamer population of the starting amide. When the N-benzyl-N-methyl amide is used, only the normal Pummerer product is formed. In this case, the thionium ion is generated in the wrong conformation for π-cyclization to occur. The corresponding N-tert-butyl amido system, however, exists in a geometric orientation which places the benzylic group in the crucial conformation necessary for π-cyclization, and consequently, the reaction proceeds smoothly. Related cyclization reactions occur in good yield with the corresponding furanyl and cyclohexenyl N-tert-butyl amido sulfoxides. The additive Pummerer reaction of 3-phenylsulfinyl-N-benzyl-N-tert-butylacrylamide gave products derived from both 5- and 6-exo trig cyclizations. Intramolecular electrophilic aromatic substitution via six-membered ring closure ultimately afforded a dihydropyridone. The competitive process involving ipso attack of the aromatic ring on the thionium ion generates a spiro cyclohexadienyl cation that undergoes fragmentation of the adjacent σ-bond. The resulting acyl iminium ion is converted to N-tert-butyl-2-phenyl-3-phenylsulfinylacrylamide upon aqueous workup. Only cyclizations leading to five-membered rings occur with the corresponding indolyl and alkenyl N-tert-butyl amido sulfoxides.