Strongly Oxidizing Thiapyrylium Salt for Organophotoredox Catalysis

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: May 1, 2025

Photoredox catalysis has garnered significant attention in organic chemistry for its ability to promote chemical transformations under visible-light irradiation. To date, research on salt-based organophotoredox catalysts mainly concentrated the development of oxygen- and nitrogen-based such as acridinium pyrylium salts, whereas sulfur-containing have received far less attention. Herein, we report a strongly oxidizing tert-butyl-substituted thiapyrylium catalyst (tBu-TTPP) that exhibits high excited-state reduction potential (E1/2(C*/C•-) = +2.23 V vs SCE) can be activated by blue LEDs. The tBu-TTPP provided promising results various photoredox reactions, radical-cation Diels-Alder trifluoromethylations, [4 + 2] annulation alkynes thiophene, C-N cross-coupling fluoroarenes, demonstrating catalysis.

Language: Английский

Efficient Synthesis and Iodine‐Functionalization of Pyrazoles via KIO3/PhSeSePh System under Acidic Conditions

Chemistry - An Asian Journal, Journal Year: 2024, Volume and Issue: 19(23)

Published: Aug. 20, 2024

Abstract This manuscript reports a novel method for the direct iodination of C‐4 pyrazole ring generated in situ by reaction 1,1,3,3‐tetramethoxypropane and various hydrazines. In this approach, potassium iodate (KIO 3 ) is used as iodinating agent (PhSe) 2 catalysts under acidic conditions. protocol provides convenient efficient synthesis 4‐iodo‐1‐aryl‐1 H ‐pyrazoles, valuable intermediates several different coupling reactions.

Language: Английский