Reaction of [hydroxy(tosyloxy)iodo]benzene and [hydroxy(mesyloxy)iodo]benzene with trimethylsilyl enol ethers. A new general method for .alpha.-sulfonyloxylation of carbonyl compounds

Abstract

ChemInform Abstract The trimethylsilyl enol ethers (I) react with hydroxy(mesyloxy or tosyloxy)iodobenzene (II) to give the α-sulfonyloxycarbonyl compounds (III).

A facile asymmetric synthesis of (S)-duloxetine

“…10 The catalytic reaction of 1 (substrate/catalyst molar ratio 500) with Cp*RhCl[(S,S)-TsDPEN], 11 where Cp* = pentamethylcyclopentadienyl, effectively performed with an azeotropic mixture of formic acid/triethylamine (molar ratio 5/2) in ethyl acetate to produce (S)-2-tosyloxy-1-(2-thiophenyl)ethanol 2, [α] D 27 = -31.3 (c 1.08, CHCl 3 ), in 95% yield with 95% ee. It should be noted the observed enantioselectivity was similar to this reported in the corresponding α-chloroketone, 12 and thus represented a first successful application of α-tosyloxy heteroaryl ketone in transfer hydrogenation with high enantioselectivity.…”

7.07 α-Oxygenation of Carbonyl Compounds

“…This approach gives control of regioselectivity, as well as better yields with some substrates. 135 7.07.5.2.1 In situ formation of the HTIB reagent [Hydroxy(tosyloxy)iodo]arenes can be formed in situ by treating various iodine(III) precursors, such as DIB or iodosylbenzene, with p-toluenesulfonic acid (TsOH). 130,136 4-Iodotoluene difluoride is an efficient a-oxygenation reagent in the presence of oxygen-containing nucleophiles like TsOH, MsOH, AcOH, diphenyl phosphate, MeOH, EtOH, and i PrOH (Scheme 51(a)).…”

Hypervalent iodine reagents in the total synthesis of natural products

“…337,338 Instead, they utilized a two step protocol also developed by Moriarty and co-workers, 339,340 where a silyl enol ether was prepared and treated with iodine(III) in the presence of a Lewis acid in methanol to give the α-oxidized product (Scheme 59). An analogous protocol can be used to promote a α-sulfonyloxylation, 341 as reported in the synthesis of (+)-duloxetine.…”