Nobuo Ishikawa

The cross-coupling of aryl halides with grignard reagents catalyzed by iodo(phenyl)bis(triphenylphosphine)palladium(II)

Abstract The palladium-catalyzed cross-coupling of aryl halides with Grignard reagents affords a variety of biaryls and alkylbenzenes. Based on the proposed catalytic cycle, the complex (PPh 3 ) 2 Pd(Ph)I was found to be a convenient and general catalyst. Certain features of cross-coupling with this catalyst are described.

(Trifluoromethyl)ketene silyl acetal as an equivalent to the trifluoropropionic ester enolate: preparation and aldol-type reactions with acetals

Abstract The title reagent, readily prepared from methyl β,β,β-trifluoropropionate with trimethylsilyl triflate, is shown to react with a broad variety of acetals to provide the corresponding α-CF 3 β-alkoxy esters in good yields.

Alpha-Acylation and -allylation of β,β,β-trifluoropropionic esters via the ketene silyl acetals

Abstract α-Acylation of the ketene silyl acetal of methyl β,β,β-trifluoropropionate and α-allylation via the ester enolate Claisen rearrangement of the 2-alkenyl trifluoropropionates are described which provide the corresponding α-CF 3 β-ketoesters and α-CF 3 γ,δ-unsaturated acids, respectively.

Preparation of trifluoromethylated allylic alcohols from trifluoroacetaldehyde and organometallic compounds

Abstract A number of allylic alcohols bearing a trifluoromethyl group at the α- or γ-position, and α-trifluoromethylated γ-enols and -ynols were prepared by the reaction of trifluoroacetaldehyde with a variety of organometallic compounds. Most of the Reformatsky- or Grignard-type reactions required promotion by ultrasonic irradiation.

Palladium metal-catalyzed cross-coupling of aryl iodides with arylmagnesium bromides. Synthesis of fluorobiphenyls

Abstract Palladium metal functions as catalyst in the coupling of iodobenzene with phenylmagnesium bromide. For practical purposes, palladium(II) chloride was used instead, since it is converted to palladium metal during the course of the reaction. A high catalytic effect of palladium(II) chloride at low concentrations (saturated solutions in tetrahydrofuran,

Ultrasound-promoted direct carboxylation of perfluoroalkyl iodides

Abstract Perfluoroalkyl iodides were directly carboxylated with Zn and CO 2 under ultrasonic irradiation affording the corresponding perfluoroalkanoic acids.

The reaction of 2,2,2-trifluoroethyl iodide with sodium phenolate. A novel competition between substitution and elimination reactions

Das Trifluorathyljodid (I) reagiert mit Thiophenolat in Dimethylformamid bei Raumtemperatur zum Substitutionsprodukt (III), dagegen mit Natriumphenolat erst bei 80°C zu einem Gemisch der Verbindungen (V)-(IX).

Preparation of 2-fluoromalonic esters and related compounds from hexafluoropropene

Abstract Dimethyl and diethyl fluoromalonates were prepared from hexafluoropropene by its exhaustive alcoholysis or alternatively its ammonolysis and alcoholysis. Fluoromalonates thus obtained or their alkylated derivatives were condensed with o-phenylenediamine or its substituted derivatives to give a number of 1H-3-fluoro-1,5-dibenzodiazepin-2,4(3H,5H)-diones.

Optically active perfluoro-2-propoxypropionic acid: A new chiral reagent for 19F NMR study

Abstract Perfluoro-2-propoxypropionic acid, which was prepared by the anionic dimerization of hexafluoro-1,2-epoxypropane, was optically resolved via diastereomeric salt formation with chiral amines. The optically pure (+) and (−) perfluoro-2-propoxypropionic acids thus obtained were found to be a convenient chiral reagent for determining enantiomeric compositions of α-amino acids by means of 19 F nmr analysis.

Preparation of benzoheterocycles containing a chlorofluoromethyl group using the ‘Yarovenko reagent’

Abstract ortho -Bifunctional benzenes such as 2-aminophenol o-phenylenediamine, 2-aminothiophenol, 2-aminobenzamide and catechol reacted very easily with 2-chloro-1,1,2-trifluoroethyldiethlylamine, the ‘Yarovenko reagent,’ affording 2-(chlorofluoromethyl)benzoxazole, -benzoimidazole, -benzothiazole, 2-(chlorofluoromethyl)-4-quinazolone and 2-diethylamino-2-(chlorofluoromethyl)dioxole respectively.