Hydroxy(tosyloxy)iodo]benzene mediated alpha-azidation of ketones

Reaction of various ketones with [hydroxy(tosyloxy)iodo]benzene (HTIB) followed by treatment of the alpha-tosyloxy ketones thus generated in situ with NaN3 offers a one-pot procedure for the synthesis of alpha-azido ketones. The HTIB used in this conversion may also be generated in situ by using iodosobenzene in combination with p-toluene-sulphonic acid.     

A Facile [hydroxy(tosyloxy)iodo]benzene Mediated Synthesis of Symmetrical Triazolo-[3,4-b]-1,3,4-Thiadiazines

Synthesis of the title compounds has been accomplished by a one-pot procedure involving the reaction of 3-substituted-4-amino-5-mercapto-1,2,4-triazoles and a variety of heterocyclic ketones in the presence of [hydroxy(tosyloxy)iodo]benzene.     

Synthesis of Flavones from the Hypervalent Iodine Oxidation of Flavanones Using [Hydroxy(tosyloxy)iodo]benzene in Methanol

Hypervalent iodine oxidation of several flavanones (1a-1f) using (hydroxy(tosyloxy)iodo] benzene in methanol offers a new method for the synthesis of flavones (2a-2f).     

[Hydroxy(tosyloxy)iodo]benzene as Thermal initiator for the Radical Polymerization of Methyl Methacrylate

Abstract

The thermal polymerization of methyl methacrylate in a solution of N,N-dimethylacetamide has been studied using [hydroxy(tosyloxy)- iodo]benzene (HTIB) as the initiator. The rate of polymerization was a direct function of the monomer and initiator concentrations. The initiator and monomer exponent values expressing this dependence were found to be 1.0 and 0.8, respectively. The overall activation energy of polymerization was estimated to be 45 kJ·mol^?-1. The polymerization was inhibited in the presence of hydroquinone. The effect of various solvents on the polymerization rate was studied. The polymer prepared with HTIB (0.47 × 10^?3 mol·L^?-1) had a number-average molecular weight of 138,000 and a glass transition temperature of 106°C. The polymer showed good thermal stability as determined by thermogravimetric analysis.     

Concise and Efficient Synthesis of 1H-Pyrazoles: Reaction of [Hydroxy(tosyloxy)iodo]benzene with Ethyl 2,3-Dioxobutanoate-2-arylhydrazones

Ethyl 2,3-dioxobutanoate-2-arylhydrazones 1 on treatment with [hydroxy(tosyloxy)iodo]benzene 2 at reflux temperature and followed by heating in the presence of N-ethyldiisopropylamine afforded the cyclized ethyl 1-aryl-4-hydroxy-1H-3-pyrazolecarboxylates 4 in good yield.     

[Hydroxy(tosyloxy)iodo]benzene: A Tosyloxylating Agent with Selectivity for Ketones in the Reactions with Benzalacetones

The treatment of enolizable ketones containing a conjugated double bond, namely benzalacetones with [hydroxy(tosyloxy)iodo]benzene, leads to regioselective tosyloxylation, thereby giving new compounds (α-tosyloxybenzalacetones).     

Hypervalent Iodine in Synthesis XXIII: Oxidation with [Hydroxy(tosyloxy)iodo]benzene: Selective Oxidation of Sulfides to Sulfoxides

Alkyl-and aryl-sulfides can be selectively oxidated to their corresponding sulfoxides with excellent yields under mild conditions by [hydroxy (tosyloxy)iodo]benzene. Morever, [hydroxy (((+)-10-camphorosulfonyl)oxy)iodo]benzene as the chiral oxidizer, can be used to oxidate unsymmetric sulfides to sulfoxides with a few %ee to some extent.     

Photopolymerization of Methyl Methacrylate and other Acrylates with the Use of [Hydroxy(tosyloxy)iodo]benzene as Photoinitiator

Abstract

[Hydroxy(tosyloxy)iodo]benzene (HTIB) was found to be an effective photoinitiator for the solution polymerization of methyl methacrylate. The polymerization is strongly inhibited in the presence of hydroquinone, it is not affected by air, and it is favored in the presence of nucleophilic solvents. A kinetic study of solution polymerization in N,N-dimethylformamide indicated a free radical polymerization mechanism involving complexation of initiator molecules with the solvent prior to radical generation, and bimolecular termination of chain radicals. Methyl acrylate and 2-hydroxyethyl methacrylate were also polymerized with HTIB as photoinitiator, but styrene could not be polymerized under similar conditions.     

Synthesis of isoxazoline N-oxides via [hydroxy(tosyloxy)iodo]benzene (HTIB)-mediated oxidative N-O coupling

An HTIB mediated oxidative N-O coupling strategy for the synthesis of some isoxazoline N-oxide derivatives from β-hydroxyketoximes is described, along with a comparative study of the efficiency of N-O coupling in two different solvents. A plausible mechanism for the conversion is proposed.     

Solvent-free facile synthesis of novel α-tosyloxy β-keto sulfones using [hydroxy(tosyloxy)iodo]benzene

A facile, general and high yielding protocol for the synthesis of novel α-tosyloxy β-keto sulfones is described utilizing relatively non-toxic, [hydroxy(tosyloxy)iodo]benzene, under solvent-free conditions at room temperature.     

Synthesis of spirodienones by intramolecular ipso-cyclization of N-methoxy-(4-halogenophenyl)amides using [hydroxy(tosyloxy)iodo]benzene in trifluoroethanol

Spirodienones bearing the 1-azaspiro[4.5]decane ring system have been synthesized from N-methoxy-(4-halogenophenyl)amides by the intramolecular ipso attack of a nitrenium ion generated with [hydroxy(tosyloxy)iodo]benzene in trifluoroethanol.     

Convenient,Solvent-Free Method for Preparation of [Hydroxy(phosphoryloxy)iodo]arenes

A convenient, solvent-free method for preparation of [hydroxy(phosphoryloxy)iodo]arenes is reported. (Diacetoxyiodo)benzene or other hypervalent iodine reagents and phosphates are simply blended and ground for several minutes in an agate mortar, giving good yields of [hydroxy(phosphoryloxy)iodo]arenes with excellent purities.     

A novel one-pot synthesis of 3-carbomethoxy-4-arylfuran-2-(5H)-ones from ketones using [hydroxy(tosyloxy)iodo]benzene

A novel one-pot procedure for the synthesis of 3-carbomethoxy-4-aryl furan-2-(5H)-ones is reported via α-tosyloxylation of enolisable ketones with [hydroxy(tosyloxy)iodo]benzene, followed by treatment with potassium monomethyl malonate and K₂CO₃.     

[Hydroxy(tosyloxy)iodo]benzene-mediated regeneration of carbonyl compounds by cleavage of carbon nitrogen double bonds

[Hydroxy(tosyloxy)iodo]benzene (HTIB)-mediated regeneration of carbonyl compounds from various derivatives of carbonyl compounds of aryl and heteroaryl hydrazines containing adjacent nitrogen atoms is reported. These types of hydrazones cleaved oxidatively, giving back carbonyl compounds with HTIB, while cyclisation occurred with iodobenzene diacetate (IBD).     

Reactions promoted by [hydroxy(tosyloxy)iodo]benzene in pyrazino[1,2-b]isoquinolines

The hypervalent iodine reagent PhI(OH)OTs (HTIB) promoted oxidative demethylation of 1,4-hydroquinone methyl ethers to give quinones in a quantitative conversion. The efficacy of this reaction, that has been applied to simple arene compounds and to heterocyclic systems, such as 2-isopropoxycarbonyl-7,10-dimethoxy-pyrazino[1,2-b]isoquinoline-4-ones and 1,4-diones to get the corresponding 7,10-quinones (compounds 6-8), is similar to those promoted by CAN and does not require the presence of water. Instead of oxidative demethylation, HTIB promoted in 1-methoxy-pyrazino[1,2-b]isoquinoline-4-ones complex multi-step processes to give compounds 9 or 10.     

Efficient oxidation of benzylic alcohols with [hydroxy(tosyloxy)iodo]benzene under microwave irradiation

An efficient method for the oxidation of benzylic alcohols with [hydroxy(tosyloxy)iodo]benzene under solvent-free microwave irradiation conditions is described.