Showing papers by "Yasutaka Ishii published in 1999"

A new strategy for alkane oxidation with O2 using N-hydroxyphthalimide (NHPI) as a radical catalyst

Abstract: A practical catalytic method to convert alkanes into the corresponding oxygen‐containing compounds with O2 under mild conditions using N‐hydroxyphthalimide (NHPI) in the presence or absence of a transition metal was developed. Thus, cyclohexane was successfully converted into adipic acid in good conversion and selectivity by a combined catalytic system consisting of NHPI and Mn(acac)2. Lower alkane such as isobutane was converted into t‐butyl alcohol (83%) under 10 atm of air by NHPI‐Co(OAc)2 system. Alkylbenzene such as toluene was oxidized to benzoic acid in high yield (81%) under normal temperature and pressure of dioxygen in the presence of a catalytic amount of NHPI and Co(OAc)2. ESR measurements showed that phthalimide‐N‐oxyl generated from NHPI under dioxygen atmosphere is a key species in this oxidation and functions as a radical catalyst.

A New Approach for Oxygenation Using Nitric Oxide under the Influence of N-Hydroxyphthalimide.

Abstract: An approach for partial oxygenation through a carbocation as an intermediate was successfully developed by using nitric oxide under the influence of N-hydroxyphthalimide. Thus, a variety of benzylic ethers were converted into the corresponding partially oxidized compounds, which are difficult to prepare by conventional methods, in high yields. For example, the reaction of phthalane with NO in the presence of a catalytic amount of NHPI at 60 degrees C gave phthalaldehyde in 80% yield. The reaction was found to proceed through the formation of a hemiacetal, such as 1-hydroxyphthalane. In addition, 1,3-di-tert-butoxymethyl benzene afforded 1,3-benzenedicarbaldehyde in good yield. On the other hand, isochroman was converted into 1,1'-oxodiisochromane under these reaction conditions. The reaction of ethers with NO in the presence of a NHPI catalyst is thought to proceed via the formation of a carbocation as an intermediate. A possible reaction path was suggested.

Process for the preparation of organic compounds with imide catalysts

Abstract: A process of reacting (A) a compound capable of forming a stable radical which is selected from among (A1) oxygen compounds having carbon-hydrogen bonds at the position adjacent to the oxygen atom, (A2) carbonyl compounds and (A3) compounds having hydrocarbon groups bearing methyne carbon with (B) a radical-scavenging compound selected from among (B1) unsaturated compounds, (B2) compounds having hydrocarbon groups bearing methyne carbon, and so on in the presence of molecular oxygen by the use of an imide catalyst represented by general formula (1) or the like to thereby obtain an adduct of the compound (B) with the compound (A), a product of substitution of the compound (B) with the compound (A), or oxides of both. In said formula, R?1 and R2? are each hydrogen or the like, or alternatively R?1 and R2? may be united to form a double bond or an aromatic or nonaromatic ring; and X is oxygen or hydroxyl. This process makes it possible to efficiently produce various organic compounds under mild conditions through addition or substitution by the use of molecular oxygen.

Dehomologation of Aldehydes via Oxidative Cleavage of Silyl Enol Ethers with Aqueous Hydrogen Peroxide Catalyzed by Cetylpyridinium Peroxotungstophosphate under Two-Phase Conditions

Abstract: Dehomologation of aldehydes has been first successfully achieved via oxidative cleavage of silyl enol ethers, derived from aldehydes and trimethylchlorosilane, using aqueous hydrogen peroxide in the presence of a catalytic amount of peroxotungstophophate (PCWP) under phase-transfer conditions. For instance, the oxidation of 1-[(trimethylsilyl)oxy]-1-octene resulting from octanal and Me3SiCl with 35% H2O2 catalyzed by PCWP in dichloromethane at room temperature afforded the one-carbon shorter aldehyde, heptanal, in 79% yield. A variety of silyl enol ethers were also converted into one-carbon shorter aldehydes in good yields. The oxidation under homogeneous conditions using tert-butyl alcohol gave hydrolysis products such as 2-oxooctanol and octanal. It is of interest that [1-(trimethylsilyl)oxy]-1,10-undecadiene involving an enol moiety and a terminal double bond afforded exclusively 9-decenal, in which the enol moiety was selectively oxidized. A plausible reaction path for the oxidative cleavage of silyl ...

Methods of acylating adamantane, tricyclo[5.2.1.02,6], and decalin compounds

Abstract: An acylating agent of the invention includes (A) a 1,2-dicarbonyl compound or its hydroxy reductant, (B) oxygen, and (C) at least one compound selected from (c1) a metallic compound and (C2) N-hydroxyphthalimide or another imide compound. As the 1,2-dicarbonyl compound or its hydroxy reductant (A), biacetyl, 2,3-butanediolor the like canbeused. As the metallic compound (c1), cobalt acetate, or another cobalt compound, for example, can be employed. By reacting an adamantane derivative or another compound having a methine carbon atom with the acylating agent, an acyl group can be introduced to the methine carbon atom with efficiency.

Development of Novel Aerobic Oxidation Method using N-Hydroxyphthalimide as Catalyst

Abstract: Novel methods for the oxidation of alkanes with molecular oxygen using a radical catalyst, N-hydroxyphthalimide (NHPI), have been developed. Thus, a variety of alkanes such as cyclohexane, adamantane and toluene which are very difficult to be oxidized with molecular oxygen by conventional methods could be converted into the corresponding alcohols and/or carbonyl compounds in high yields. The application of the same methodology to adamantane with CO/air led to adamantanecarboxylic acid through radical carbonylation in fair yield. The reaction of benzyl ethers with NO in the presence of NHPI afforded the corresponding aldehydes in good yields. The present method provides a new class of aerobic oxidation which is refered to as radical-catalyzed autoxidation.

Acylating agents, acylation method with the use of the same and adamantane derivatives

Abstract: Acylating agents comprising: (A) a 1,2-dicarbonyl compound or its hydroxy-reduction derivative; (B) an enzyme; and (C) at least one compound selected from among (c1) metal compounds and (c2) imide compounds such as N-hydroxyphthalimide. As the 1,2-dicarbonyl compound or its hydroxy-reduction derivative (A), use may be made of biacetyl, 2,3-butanediol, etc. As the metal compounds (c1), use may be made of a cobalt compound such as cobalt acetate. An acyl group can be efficiently introduced into a methine carbon atom by treating a compound carrying a methine carbon atom such as an adamantane derivative by the above acylating agent.

Method for producing amide or lactam

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing a corresponding amide or lactam from hydrocarbons having methylene groups by one step. SOLUTION: A linear or cyclic compound having the methylene group is reacted with a nitrogen oxide in the presence of an imide compound represented by formula (1) [wherein, R1 and R2 are the same as or different from each other and each a hydrogen atom, a halogen atom, an alkyl group, an aryl group, a cycloalkyl group, a hydroxy group, an alkoxy group, a carboxy group, an alkoxycarbonyl group or an acyl group, or may form a double bond or an aromatic or nonaromatic ring by bonding to each other; X is an oxygen atom or a hydroxy group; The R1, R2, or the double bond or the aromatic or nonaromatic ring formed by bonding to each other may further have one or two N-substituted cyclic imide groups of formula (1)], and a halogen or a Beckmann's rearrangement catalyst to provide the objective corresponding amide or lactam.

Production of hydroxyketone

Abstract: PROBLEM TO BE SOLVED: To efficiently produce a corresponding hydroxyketone by oxidizing a secondary alcohol having plural hydroxy groups in the molecule by reacting the specific secondary alcohol with oxygen in the presence of a specified imide compound. SOLUTION: A secondary alcohol having plural hydroxy groups in the molecule, preferably 4-15C linear polyols or 4-15C cyclic polyols (including saccharides) is reacted with oxygen by using an imide compound of the formula (R1 and R2 are each H, a halogen, an alkyl, an aryl, a cycloalkyl, an acyl or the like; X is O or OH) as a catalyst, and a metallic compound as a cocatalyst to provide the objective ketone.

Acylating agent and acylation using the same, and adamantane derivative

Abstract: PROBLEM TO BE SOLVED: To obtain an acylating agent capable of simply and efficiently introducing an acyl group to a non-activated carbon atom, for example, even a carbon atom at the bridge head position of a polycyclic compound, by combining a specific dicarbonyl compound, oxygen, a metal compound, etc. SOLUTION: This acylating agent comprises (A) a 1,2-dicarbonyl compound or its hydroxy reduced product, preferably biacetyl, etc., (B) oxygen, and (C) (i) a metal compound, preferably a transition metal compound, concretely a cobalt compound, etc., and (ii) at least one compound selected from imide compounds of formula I (R and R are each H, a halogen, an alkyl, an aryl or the like; X is O or hydroxyl). The component A is preferably a compound of formula II (R and R are each a 1-4C alkyl, a cycloalkyl or the like; Z and Z are each O atom or hydroxyl).

A Remarkable Effect of Quaternary Ammonium Bromide for the N‐Hydroxyphthalimide‐Catalyzed Aerobic Oxidation of Hydrocarbons.

Abstract: A methodology for the aerobic oxidation of organic substrates in the absence of any metal catalyst has been established using combined catalytic system consisting of N-hydroxyphthalimide and quaternary ammonium bromide. Thus, various hydrocarbons were successfully oxidized under dioxygen atmosphere to the corresponding oxygenated compounds in good selectivities.

Production of organic sulfur acid or its salt

Abstract: PROBLEM TO BE SOLVED: To efficiently and directly produce the subject compound useful as a raw material for medicines, or the like, under relatively mild conditions by using a specific imide compound and sulfur oxide in combination. SOLUTION: (B) Sulfur oxide is reacted with (C) an organic medium in the presence of (A) an imide compound represented by the formula (R1 and R2 are each H, a halogen, an alkyl, or the like; R1 and R2 may mutually be bonded to form a double bond or an aromatic or a nonaromatic ring; X is O or hydroxyl; one or two N-substituted cyclic imide groups may further be bonded to the double bond or the aromatic or the nonaromatic ring formed by mutually bonding R1, R2 or R1 and R2) to form the corresponding organic sulfur acid or its salt. The component B preferably consists essentially of at least one kind selected from sulfur dioxide and sulfur trioxide and the component C is preferably one kind selected from a homocyclic or a heterocyclic compound having methylene group, a compound, or the like, having a methine carbon atom.

Preparation of Substituted Alkylpyrroles via Samarium-Catalyzed Three-Component Coupling Reaction of Aldehydes, Amines, and Nitroalkanes.

Abstract: Pyrroles were synthesized by three-component coupling reaction of aldehydes, amines, and nitroalkanes in the presence of a catalytic amount of a samarium species under mild conditions. The reaction is considered to involve the coupling of alpha,beta-unsaturated imines, which are provided by the samarium-catalyzed aldol-type condensation of imines generated from amines and aldehydes, with nitroalkanes. In the case of the three-component coupling of alpha,beta-unsaturated aldehydes (or ketones) with amines and nitroalkanes, alkylpyrroles were obtained by only heating in the absence of any catalyst. For instance, a mixture of butylamine, 2-butylidenecyclohexanone, and nitroethane, allowed to react at 60 degrees C for 15 h, produced isoindole, 4r, which is difficult to prepare by conventional methods, in 39% yield.

Oxidative Cleavage of vic‐Diols to Aldehydes with Dioxygen Catalyzed by Ru(PPh3)3Cl2 on Active Carbon.

Abstract: A variety of vic-diols were first successfully cleaved to the corresponding aldehydes with dioxygen catalyzed by Ru(PPh3)3Cl2 on active carbon in fair to good yields. For example, treatment of 1,2-octandiol and 1,2-cyclooctanediol with dioxygen in the presence of Ru(PPh3)3Cl2/C in PhCF3 at 60 °C for 15 h produced heptanal and 1,8-octanedial in 77% and 76% yields, respectively.

Selective Oxidation of Sulfides to Sulfoxides with Molecular Oxygen Catalyzed by N-Hydroxyphthalimide (NHPI) in the Presence of Alcohols.

Abstract: Aerobic oxidation of various sulfides using N-hydroxyphthalimide (NHPI) in the presence of alcohols was examined. For instance, the oxidation of diphenyl sulfide in the presence of cyclohexanol and a catalytic amount of NHPI in benzonitrile gave diphenyl sulfoxide in 88 % yield along with a small amount of diphenyl sulfone (7 %). The actual oxidant in this oxidation is considered to be an α-hydroxy hydroperoxide generated by the autoxidation of alcohol assisted by the NHPI which serves as the radical catalyst.

Catalyst comprising nitrogen-containing heterocyclic compound and production of organic compound using the same

Abstract: PROBLEM TO BE SOLVED: To provide a catalyst capable of introducing oxygen atom-containing groups into an organic substrate under a moderate condition. SOLUTION: This catalyst is a catalyst for reactions using an oxygen atom- containing reactant, and is composed of a nitrogen-containing heterocyclic compound represented by the formula (wherein R1 and R2 are identical or different and represent a hydrogen atom, a halogen atom, an alky group, a haloalkyl group, an aryl group, a cycloalkyl group, a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or an acyl group, R1 and R2 may be bound to each other to form a double bond or an aromatic or nonaromatic ring together with two neighboring carbon atoms, one or two heterocyclic rings containing three nitrogen atoms, shown in the formula, may be additionally formed in R1, R2, or the double bond or the aromatic or nonaromatic ring formed by binding R1 and R2 mutually; X represents an oxygen atom or a hydroxy group; Y represents a single bond, a methylene group, or a carbonyl group).

A New Approach for Oxygenation Using Nitric Oxide under the Influence of N‐Hydroxyphthalimide.

Abstract: An approach for partial oxygenation through a carbocation as an intermediate was successfully developed by using nitric oxide under the influence of N-hydroxyphthalimide. Thus, a variety of benzylic ethers were converted into the corresponding partially oxidized compounds, which are difficult to prepare by conventional methods, in high yields. For example, the reaction of phthalane with NO in the presence of a catalytic amount of NHPI at 60 degrees C gave phthalaldehyde in 80% yield. The reaction was found to proceed through the formation of a hemiacetal, such as 1-hydroxyphthalane. In addition, 1,3-di-tert-butoxymethyl benzene afforded 1,3-benzenedicarbaldehyde in good yield. On the other hand, isochroman was converted into 1,1'-oxodiisochromane under these reaction conditions. The reaction of ethers with NO in the presence of a NHPI catalyst is thought to proceed via the formation of a carbocation as an intermediate. A possible reaction path was suggested.

Carbonylation of Terminal Alkynes Using a Multicatalytic System, Pd(II)/Chlorohydroquinone/NPMoV, under Carbon Monoxide and Dioxygen.

Abstract: Carbonylation of terminal alkynes was performed using a new triple catalytic system, Pd(II)/chlorohydroquinone/NPMoV, under carbon monoxide and oxygen. For instance, phenylacetylene was converted into methyl phenylpropiolate (85%) in methanol and phenylmaleic anhydride (62%) in dioxane. The reaction did not take place in the absence of oxygen.

Oxygenation of Alkynes to α,β‐Acetylenic Ketones with Dioxygen Catalyzed by N‐Hydroxyphthalimide Combined with a Transition Metal.

Abstract: Alkynes were successfully converted into α,β-acetylenic carbonyl compounds through radical-catalyzed aerobic oxidation using N-hydroxyphthalimide (NHPI) combined with a transion metal under mild conditions.

Selective Synthesis of 1‐Alkoxy‐3‐phenylseleno‐1‐alkenes and 3‐Phenylselenoalkanals by the Reaction of Diisobutylaluminum Phenylselenolate with α,β‐Unsaturated Acetals.

Abstract: The reaction of α,β-unsaturated acetals with diisobutylaluminum phenylselenolate followed by treatment with H 2 O affords the corresponding 1-alkoxy-3-phenylseleno-1-alkenes in good yields. When aq. HCl instead of H 2 O was employed in the workup, 3-phenylselenoalkanals were formed in good yields.

Procede de preparation de composes organiques au moyen de catalyseurs imide

Abstract: L'invention concerne un procede consistant a faire reagir A) un compose susceptible de former un radical stable selectionne dans le groupe constitue A1) des composes oxygene possedant des liaisons carbone-hydrogene dans la position adjacente a l'atome d'oxygene, A2) des composes carbonyle, et A3) des composes comprenant des groupes hydrocarbones contenant du carbone de methyne, avec B) un compose de piegeage de radicaux selectionnes dans le groupe constitue par B1) des composes insatures, B2) des composes possedant des groupes hydrocarbones contenant un carbone de methyne, de facon a obtenir, en presence d'oxygene moleculaire, a moyen d'un catalyseur imide represente par la formule (1) ou analogue, un produit d'addition du compose B et du compose A, un produit de substitution du compose B et du compose A, ou des oxydes des deux composes representes par la formule (1) (ou R1 et R2 representent chacun hydrogene ou analogue, ou selon un autre mode de realisation, R1 et R2 peuvent etre lies pour former un noyau aromatique ou non aromatique a liaison double; et X represente oxygene ou hydrogene). Ce procede permet de preparer efficacement differents composes organiques dans des conditions moderees par addition ou substitution au moyen d'oxygene moleculaire.