Stereoselective Ketone Rearrangements with Hypervalent Iodine Reagents

Abstract

The first stereoselective version of an iodine(III)-mediated rearrangement of arylketones in the presence of orthoesters is described. The reaction products, α-arylated esters, are very useful intermediates in the synthesis of bioactive compounds such as ibuprofen. With chiral lactic acid-based iodine(III) reagents product selectivities of up to 73 % ee have been achieved.

Vicinal Difunctionalization of Alkenes under Iodine(III) Catalysis involving Lewis Base Adducts

“…Examples in this area include the compound [PhI(py) 2 ](OTf) 2 (2), [12] the corresponding benziodoxolone adduct 3 [13] and the chiral derivatives 4 and 5, which were introduced by Wirth ( Figure 1). [14,15] Interestingly, the solid state structure of 4 does not display any interaction between the iodine(III) center and the nitrogen atom of the pyridinyl group. In agreement with this, the reported catalysis relied on co-activation by BrØnsted acid.…”

“…In agreement with this, the reported catalysis relied on co-activation by BrØnsted acid. [15] To probe the supportive context of pyridine coordination in an iodine(III) catalyst, the aryliodine 6 was synthesized from 2-phenyl pyridine [16,17] and submitted to oxidation. Exploring several established oxidation agents, we observed that only peracetic acid provided an oxidation product (Scheme 2).…”

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

“…Their environment-friendly nature and mild reaction conditions makes them more attractive candidates for the replacements of various toxic metals in organic synthesis [ 18 – 31 ]. These reagents are more popular for their oxidizing properties [ 32 – 38 ] and electrophilic nature of different iodine(III) reagents has been explored to developed various synthetic transformation including rearrangements [ 39 – 62 ]. Hypervalent iodine chemistry has now become a well-established research area and various book chapters [ 19 – 20 27 ] and review articles [ 21 – 24 31 – 35 60 , 63 – 64 ] appeared to explain the chemistry of these reagents.…”

Hypervalent Iodine Reagents by Anodic Oxidation: A Powerful Green Synthesis

“…Hypervalent iodine reagents are widely used in modern organic synthesis . These reagents have tremendous synthetic applications, including difunctionalization of olefins and cyclopropanes, oxidative couplings, phenol dearomatizations, oxidative formation of heterocycles, aminations, halogenations, arylations, and rearrangements . In addition, a wide range of stereoselective transformations was achieved with high degree of stereocontrol using chiral hypervalent iodine reagents and catalytic systems of chiral iodoarenes and terminal oxidants .…”

“…[1][2][3][4] These reagents have tremendous synthetic applications,i ncluding difunctionalization of olefins and cyclopropanes, [5][6][7] oxidative couplings, [8][9][10] phenol dearomatizations, [11,12] oxidative formation of heterocycles, [13][14][15][16] aminations, [17,18] halogenations, [19][20][21] arylations, [22][23][24] and rearrangements. [25][26][27][28] In addition, aw ider ange of stereoselective transformationsw as achieved with high degree of stereocontrol using chiral hypervalent iodine reagents and catalytic systems of chiral iodoarenes and terminal oxidants. [29][30][31] Moreover, they are valuable reagents for the generation of carbon and heteroatom radicals where under appropriate conditions they can act as single electron oxidants.…”