Electrochemical Synthesis of β-Iodoesters by 1,2-Iodoesterization of Unactivated Alkenes with Carboxylic Acids and Tetrabutylammonium Iodide

Abstract

We report a novel and highly selective electrochemical method for the synthesis of β-iodoesters via difunctionalization of alkenes. The reaction is carried out in an undivided cell under constant current conditions without any additives, catalysts, oxidants, and sacrificial reagents. Inexpensive and readily available tetrabutylammonium iodide not only acts as an electrolyte but also serves as an iodine source. The reaction shows high selectivity and good functional group tolerance, providing products in yields of up to 98%. This method is applicable not only to the iodofunctionalization of alkenes but also to the chloro- and bromofunctionalization of alkenes. The successful modification of drugs and natural products demonstrates the potential utility of this approach.

Visible-Light Induced Radical Addition–Elimination Reaction for Constructing Allylic Sulfones from Sulfonyl Chlorides and Allyl Bromides

“…Photoexcited Ir­[dF­(CF 3 )­ppy] 2 (dtbbpy)­PF 6 * generated from blue light irradiation is oxidatively quenched by sulfonyl chloride 1 via a single electron transfer (SET) process, giving sulfonyl radical I and Ir­(IV) with the release of Cl – . Subsequently, the SET between Cl – ( E ox = +0.815 V) and Ir­(IV) [ E 1/2 (Ir IV /Ir III ) = +1.69 V vs SCE] generates Ir­(III) and Cl 2 respectively, completing the photocatalytic cycle. Sulfonyl radical I attacks the double bond of allylic bromide 2 , forming radical intermediate II , which is then transformed into the corresponding allylic sulfone 3 through the release of a bromine radical.…”

Electricity-driven 1,4-alkoxydimerization of alkenes via radical–polar crossover

“…9 Electric current is a superior alternative to harmful external redox reagents and expensive metal catalysts. 10 Electrochemistry also offers higher efficiency and selectivity. By fine-tuning the current and applied potential, the selectivity of products in the redox process can be better controlled, which is not possible with traditional redox reagents.…”