Dimethyl Sulfoxide Provides Three Different Units in Synthesis of Chroman-4-ones Containing Sulfur and a Quaternary Carbon Center under HOAc Conditions

Abstract

HOAc-promoted construction of chroman-4-ones with a sulfur atom and an α-carbonyl quaternary carbon center directly from ortho-hydroxyacetophenones and DMSO is described. In these unique reactions, DMSO is activated by HOAc and provides three different units (CH2, CH2OH, and CH2SMe) in the target molecules. This reaction displays good substrate scope and reaction yields with a series of substitutes. The mechanism showed that the three units were formed in sequential order.

Utilization of DMSO as a solvent-cum-reactant: synthesis of fused 2-aryl-4-methylquinolines

“…In this process, DMSO introduces three distinct units (CH 2 , CH 2 OH, and CH 2 SMe) into the resulting molecules (Scheme 1b). 9 Nonetheless, this is the single report where DMSO incorporating three carbon atoms into the target molecule. It should be mentioned that in all these cases, the transfer of carbon atoms is executed by the capture of the sulfenium ion, which is generated in situ from the activation of DMSO in the presence of oxidants such as K 2 S 2 O 8 and Selectfluor.…”

DMSO promoted catalyst-free oxidative C–N/C–O couplings towards synthesis of imidazoles and oxazoles

“…Among widely used organic solvents, dimethyl sulfoxide (DMSO) can be used as an oxidant as well as a source of carbon or sulfur or oxygen for subsequent diverse transformations. 2 In this respect, DMSO-mediated dehydrogenative oxidations such as Swern, Parikh Doering, and Pfitzner Moffatt oxidations are well known in addition to oxygen-adding oxidations such as the Kornblum oxidation in which DMSO acts as an oxygen source. 3…”