Synthesis of Hypervalent Iodine Diazo Compounds and Their Application in Organic Synthesis

Abstract

Hypervalent iodine diazo reagents with electron‐withdrawing groups (EWG) connected to diazo methyl center were a type of donor‐acceptor diazo compounds with potential reaction abilities similar to ordinary diazo compounds. Although several hypervalent iodine diazo reagents were synthesized and used in the nucleophilic substitution reactions as early as 1994, the synthesis and application of new iodine(III) diazo reagents have only been reported to a certain extent in recent years. In the presence of rhodium catalyst, photocatalyst, or nucleophiles, hypervalent iodine diazo reagents can be converted into rhodium‐carbenes, diazomethyl radicals, ester radicals or nucleophilic intermediates, which can be used as key intermediates for the formation of chemical bonds. The aim of this review is to give an overview of hypervalent iodine diazo compounds in organic synthesis.

Alkoxy Diazomethylation of Alkenes by Photoredox-Catalyzed Oxidative Radical-Polar Crossover

“…Originally, we envisioned that an appropriate Ru(II) photocatalyst, upon visible light irradiation, would generate excited state Ru(II)* able to undergo single-electron reduction with diazomethyl-substituted hypervalent iodine reagents and deliver diazomethyl radical int-I (Figure ). The latter species attacked the corresponding alkene and generate int-II . Ru(III) species would be an adequate oxidant to undergo single-electron transfer with int-II and generate benzylic cation int-III .…”