Continuous Bioinspired Oxidation of Sulfides

Abstract

A simple, efficient, and selective oxidation under flow conditions of sulfides into their corresponding sulfoxides and sulfones is reported herein, using as a catalyst perselenic acid generated in situ by the oxidation of selenium (IV) oxide in a diluted aqueous solution of hydrogen peroxide as the final oxidant. The scope of the proposed methodology was investigated using aryl alkyl sulfides, aryl vinyl sulfides, and dialkyl sulfides as substrates, evidencing, in general, a good applicability. The scaled-up synthesis of (methylsulfonyl)benzene was also demonstrated, leading to its gram-scale preparation.

“Green Is the Color”: An Update on Ecofriendly Aspects of Organoselenium Chemistry

“…In the recent past, following the idea of applying selenium-containing catalyst in a continuous flow system, Santi et al [ 120 ] promoted the synthesis of sulfoxides 91 and sulfones 92 through a bioinspired approach ( Scheme 43 ). In this process, SeO 2 90 was oxidized to perselenic acid; adeguately tuning the amount of H 2 O 2 provided the products of interest in isolated yields ranging from 74% to >99%, by reacting with a wide range of sulfides 89 .…”

Q-Tube®-Assisted Alkylation and Arylation of Xanthines and Other N-H-Containing Heterocycles in Water

“…4.4'-(4.6-Dinitro-1.3-phenylene)bis(1-methylpiperazine) (17) was prepared according to the general procedure, starting from 1.68 mmol (0.186 mL) of 1-methyl-piperazine 12, 1.68 mmol (0.233 g) of potassium carbonate, and 0.84 mmol (0.2 g) of 1,3-dichloro-4,6dinitrobenzene in 1.4 mL of H 2 O. The reaction mixture was extracted with EtOAc (3 × 20 mL).…”

“…As part of our ongoing efforts to ameliorate synthetic procedures also using nonconventional technologies [13][14][15][16][17][18] to enable them to meet the principles of green chemistry, and intrigued by the manifold biological activities exerted by xanthines [4], we sought to develop a flexible synthetic procedure intended to improve caffeine synthesis from a green chemistry perspective and, at the same time, prepare a series of diversely N-7 substituted xanthine derivatives. With this aim, we chose to perform these reactions in the Q-tube® apparatus, which allows reactions to be performed under high pressure, overcoming the solvent boiling point and, as a result, increasing the reaction pressure and temperature, thus reducing the reaction time.…”

Synthesis of (E)‐β‐Iodovinyl Sulfones via Photoredox Catalyzed Difunctionalization of Terminal Alkynes

“…The β-iodovinyl sulfide IV on oxidation in the presence of selenium dioxide [22] affords (E)-β-iodovinyl sulfones. The selective formation of E-isomer can be attributed to the equal abundance of the vinyl radical E-form III and Z-form IIIa.…”