λ³‐Iodanes as Visible Light Photocatalyst in Thioacetalization of Aldehydes

Abstract

Introduction of an iodine(III) reagent as visible‐light photocatalyst for chemoselective dithioacetalization has been the limelight of the current methodology. The mechanistic investigations reveal that the reactions proceeded via radical pathway upon light induced hemolytic cleavage of C–I bond of the catalyst. Several dithioacetals were easily accessible at room temperature and environmentally benign condition.

Iodine-based reagents in photoredox-organocatalysis

“…74 Recently, the application of hypervalent iodine reagent with organo-photocatalyst in rearrangement reactions for the construction of highly functionalized molecules via dual catalysis has become popular. 75 The first visible light-induced Smiles rearrangement 76 was reported by Chen and coworkers in 2019 for the synthesis of hydroxybenzophenone derivatives from aryl ketoacids via radical rearrangement (Figure 12). 77 For this transformation the combination of 2 mol % of 9-mesityl-10-methylacridinium perchlorate (Acr-Mes + ClO4 − ) as organo-photocatalyst and 20 mol % of acetoxybenziodoxole (BI-OAc) were used under 4 h of irradiation with blue light to isolate good to excellent yield of hydroxybenzophenone derivatives 31 from ortho ketoacid substituted biaryl ethers 30.…”

t BuOLi-promoted terminal alkyne functionalizations by aliphatic thiols and alcohols

“…16 The dithioacetals are obtained from aldehydes and non-conventional starting materials using Lewis acids, iodine catalyst and visible light. 17 However, selective dithioacetalization of alkyne by dithiol is challenging because it leads to both Markovnikov and anti-Markovnikov products with poor stereoselectivity.…”