Selectfluor-Mediated Synthesis of β-Acyl Allyl Sulfones/β-Acyl Allyl Benzotriazoles from Ketones/Acetylenes, Aryl Sulfinates/Benzotriazole, and DMSO as a Dual-Carbon Synthon

Abstract

A Selectfluor-mediated approach for the synthesis of β-acyl allyl sulfones/β-acyl allyl benzotriazoles with excellent atom economy from readily available acetophenones/aryl acetylenes, aryl sulfinates/benzotriazoles, and dimethyl sulfoxide (DMSO) is described. In this protocol, DMSO acts as a dual-carbon synthon, resulting in a transition-metal-free construction of two C–C and one C–S or two C–C and one C–N bonds in one pot. This approach is extended to generate chemically diverse compounds. Additionally, β-acyl allyl sulfones/β-acyl allyl benzotriazoles were prepared from acetylenes instead of acetophenones.

Visible Light Induced C2 Alkylation of 2H‐Benzoxazoles with Cycloalkanes and Ethers via Selectfluor‐Mediated Oxidation

“…Then, the intermediate H was deprotonated to a radical I . A single‐electron transfer (SET) was followed between radical I and another selectfluor giving iminium ion J and N radical cation B [42] . Ultimately, C2‐alkylated product K would be obtained by further deprotonation of J [43,44] …”

DMSO as a dual carbon synthon in one-pot tandem synthesis of N-alkylated quinazolinones from anthranilamides and acetophenones

“…Based on the above preliminary mechanistic experiments and previous literature reports 9–11 a plausible reaction mechanism has been designed, as shown in Scheme 5. This reaction cascade starts with the activation of DMSO by K 2 S 2 O 8 to produce the reactive ulfonium ion A , which upon condensation with 2-aminobenzamide gives intermediate B .…”

“…9,10 However, the use of DMSO as a two-carbon source is not much explored. 11 In continuation of our current research program that specifically uses DMSO as a carbon synthon, 10 we report herein that DMSO is a dual-carbon source in the synthesis of N -alkylated quinazolinones from readily available anthranilamide and acetophenones under transition metal-free conditions. In this method, DMSO is being used as a solvent as well as a two-carbon source, thereby playing a dual role.…”

Transition-metal-free C–S bond cleavage and transformation of organosulfur compounds

“…32 c Very recently, Rode and co-workers prepared β-acyl allyl benzotriazoles 73 and sulfones 74 enabled by the Selectfluor-DMSO system with acetophenones/aryl acetylenes and benzotriazoles/sulfinates (Scheme 14d). 33 It is crucial to note that DMSO is provided as both a methylene (CH 2 ) or methenyl (CH) and solvent source in the above reactions.…”