Masanori Sawaguchi

Fluorocyclization of unsaturated alcohols and carboxylic acids by iodotoluene difluoride and amine-HF complexes

Abstract In the presence of amine-HF complexes, iodotoluene difluoride reacted with unsaturated alcohols and carboxylic acids to give cyclic fluoroethers and fluorolactones, respectively.

Electrochemical fluorination of β-dicarbonyl compounds using p-iodotoluene difluoride as a mediator

Abstract The selective and direct introduction of the fluorine atom into the α-position of β-dicarbonyl compounds was electrochemically achieved using iodotoluene difluoride as the mediator. The resulting α-fluoro-β-dicarbonyl compounds are important building blocks for biologically active compounds.

Fluorinative ring-expansion of cyclic ethers using p-iodotoluene difluoride. Stereoselective synthesis of fluoro cyclic ethers

Fluorinated five- to seven-membered cyclic ethers were stereoselectively synthesized from four- to six-membered cyclic ethers having an iodoalkyl substituent by fluorinative ring-expansion reaction using p-iodotoluene difluoride.

Fluorination of alkenes by iodoarene difluorides

Abstract This paper reviews the fluorination reaction of alkenes using iodoarene difluorides. It is particularly noted that an unusual fluorination reaction of alkenes such as fluorinative ring contraction and fluorocyclization reaction as well as the simple vic -difluorination selectively takes place using iodotoluene difluoride and amine-HF complexes.

Anodic fluorination of phenols using Et3N-5HF electrolyte

Abstract In the presence of Et3N-5HF electrolyte, anodic fluorination of phenols (1) successfully afforded 4,4-difluorocyclohexa-2,5-diene-1-ones (11), which were readily converted to p-fluorophenols (9) in good yields by the subsequent reduction with Zn in acidic aqueous solutions. We have revealed some novel information on the oxidation mechanism of 1, which is well supported by the cyclic voltammogram of 1 in Et3N-5HF.

Deiodinative fluorination of alkyl iodide with p-iodotoluene difluoride

Abstract Oxidative fluorination of alkyl iodides with p -iodotoluene difluoride ( 4 ) was carried out. In the presence of Et 3 N–4HF, the fluorination reaction of prim -alkyl iodides selectively took place at the iodine position under mild conditions to give the corresponding alkyl fluorides in good yields.

Stereoselective synthesis of 5-7 membered cyclic ethers by deiodonative ring-enlargement using hypervalent iodine reagents.

Stereoselective synthesis of 5-7 membered cyclic ethers was achieved by deiodonative ring-enlargement of cyclic ethers having an iodoalkyl substituent. The reaction took place readily under mild conditions using hypervalent iodine compounds and an acetoxy or a trifluoroacetoxy group was introduced into the rings depending on the hypervalent iodine reagent employed. The use of hexafluoroisopropanol (HFIP) as solvent is critical.

PREPARATION OF AROMATIC FLUORIDES : FACILE PHOTO-INDUCED FLUORINATIVE DECOMPOSITION OF ARENEDIAZONIUM SALTS AND THEIR RELATED COMPOUNDS USING PYRIDINE -NHF

Abstract By employing pyridine–nHF solution, the photo-induced fluorinative decomposition of arenediazonium salts (ArN2BF4) (fluoro-dediazoniation) and the related compounds, such as quinonediazides and triazenes, has been successfully carried out to produce the corresponding aromatic fluorides (ArF) in good yields. The rate in the fluoro-dediazoniation of para-substituted ArN2BF4 in pyridine–nHF solution did not obey the classical Hammett equation but conformed well to Tafts treatment [dual substituent parameter relationships (DSP)]. In the thermal fluoro-dediazoniation of ArN2BF4 the rate of reaction was significantly influenced by the substituents in the substrates. On the contrary, only a slight effect by the substituents was observed on the rate of the photo-induced fluoro-dediazoniation of ArN2BF4.

Anodic oxidative fluorination of 2,6-di-tert-butylphenols

Abstract In the presence of Et 3 N–5HF electrolyte, anodic fluorination of 2,6-di- tert -butylphenols with or without a substituent X (halogen) at its para -position ( 1a – c ) successfully afforded 4,4-difluoro-2,6-di- tert -butylcyclohexa-2,5-diene-1-one ( 2 ), which was readily converted to 4-fluoro-2,6-di- tert -butylphenol ( 3 ) in good yields by the subsequent reduction with Zn in acidic aqueous solutions. We revealed some novel information on the electrochemical oxidative fluorination mechanism of 1a – c , which is well supported by the product distribution curve and the cyclic voltammogram of the possible oxidative products, as well as that of 1a in Et 3 N–5HF.