Norio Kunieda

Synthesis of optically active 4-hydroxyalk-2-enenitriles; Reaction of optically active 2-(p-chlorophenylsulfinyl)acetonitrile with aldehydes in the presence of piperidine in acetonitrile

Abstract Reaction of optically active 2-(p-chlorophenylsulfinyl)acetonitrile ((R)- 1a ) with aldehydes, in the presence of piperidine in acetonitrile at r.t., gave optically active 4-hydroxyalk-2-enenitriles in good optical and chemical yields. The absolute configuration of (−)-4-hydroxypent-2-enenitrile, predominantly obtained by the reaction of (R)- 1a with propanal, was determined to be R.

A new type grignard reagent derived from ethyl α-phenylsulfinylacetate and ethylmagnesium halides

Bei der Behandlung mit den Grignardverbindungen (II) entstehen aus dem Sulfoxidketon (I) die Grignardverbindungen (III), die mit weiterem Grignardreagens zu den Carbinolen (IV) reagieren.

THE PREPARATION OF OPTICALLY ACTIVE β-KETO SULFOXIDES BY THE REACTION OF α-LITHIOMETHYL p-TOLYL SULFOXIDE WITH ETHYL CARBOXYLATES IN THE PRESENCE OF (—)-SPARTEINE

Abstract Treatment of 2 equivalents of racemic α-lithiomethyl p-tolyl sulfoxide (1) with ethyl carboxylates (2, C2H5O—CO—R) possessing a variety of groups R in the presence of (−)-sparteine afforded the corresponding optically active β-keto sulfoxides (3, p-CH3C6H4—SO—CH2—CO—R) together with optically active methyl p-tolyl sulfoxide which has the opposite configuration to 3.

OXYGEN EXCHANGE AND RACEMIZATION REACTIONS OF DIARYL SULFOXIDES IN SULFURIC ACID IN THE PRESENCE OF POTASSIUM CHLORIDE

Abstract The mechanism of the concurrent oxygen exchange and racemization reactions of sulfoxides with chloride ion in sulfuric acid 64.7–80.2% has been studied. We have found that the rate of oxygen exchange of 18O-labeled and optically active phenyl p-tolyl sulfoxide becomes identical to that of racemization by the addition of at least 0.08 mol/l potassium chloride to sulfuric acid media. The rate of the racemization cannot be correlated with H A, and the steric effect of substituent is not very large. Based on these observations, a mechanism (Scheme II) which does not include the rate-limiting formation of the chlorosulfonium ion intermediate may be suggested as most plausible for the reaction.

SULFINIC ACIDS AND SULFINIC ESTERS

Sulfinic acids are formed readily either by reduction of sulfonyl chlorides with zinc and alkaline solution or by alkaline hydrolysis of thiolsulfonates. Unlike the sulfonic acid, the sulfinic acid retains a lone electron pair on the sulfur atom and hence often behaves as a nucleophile. At the same time, the sulfinic acid is a strong acid and considered to be a key intermediate in the oxidation of the mercaptan to the corresponding sulfonic acid. Although most sulfinic acids are quite reactive, the chemistry of these acids and their esters are relatively unexplored. However, it will not be long before the chemical behavior of sulfinic acid will be uncovered, like that of sulfoxides.

Vinyl Polymerization Initiated by the Cycloamylose/Metal Ion System in Water

Abstract The polymerization of vinyl monomers, methyl methacrylate (MMA), benzyl methacrylate (BMA), styrene, and acrylonitrile has been carried out using the cycloamylose/metal ion systems in water. We have found that the α-, β-, and γ-cyclodextrins have an ability to initiate the polymerization of MMA and BMA in combination with Cu(II) or Fe(III) ions.

KINETIC STUDIES ON THE ACID-CATALYZED PUMMERER REACTION OF α-(METHYLSULFINY)ACETOPHENONES

Abstract The kinetic behavior of the acid-catalyzed Pummerer reaction of α-(methylsulfinyl)acetophenones in dilute hydrochloric acid has been studied in detail. The kinetic data were analyzed in the light of correlations between the reaction rates and acidity functions, activation parameters, solvent isotope effects, polar effects of substituents, etc. Moreover, 18O-tracer experiments were also carried out using acid media containing H2 18O. Based on these observations, a plausible mechanism for this reaction has been discussed.

Vinyl Polymerization Initiated by the Methylated Cyclodextrin/Metal Ion System in Water

Abstract The polymerization of the vinyl monomers methyl methacrylate (MMA), benzyl methacrylate, and styrene, has been carried out using methylated cyclodextrins, for example, heptakis(2,6,0-dimethyl)-β-cyclodextrin, and heptakis (2,3,6-0-trimethyl)-β-cyclodextrin. These methylated cyclodextrins were found to initiate polymerization of the vinyl monomers in combination with water and a small amount of Cu(II) ion, in analogy with β-cyclo-dextrin (β-CD). Generally, the initiating ability of the methylated cyclodextrins/Cu(II) ion system for the polymerization of MMA was larger than that of the β-CD/Cu(II) ion system. Moreover, the introduction of a phosphate group into a methylated cyclodextrin molecule was found to increase the initiating ability for the polymerization of MMA.

Vinyl Polymerization Initiated by Cycloheptaamylose Phosphate Ammonium Salt/Metal Ion System in Water

Abstract Cycloheptaamylose phosphate ammonium salt (β-PCD) was found to initiate the radical polymerization of vinyl monomers in combination with water and a small amount of Cu(n) or Fe(III) ion, in analogy with the cycloheptaamylose (β-cyclodextrin:β-CD). The initiating ability of this system was larger than that of the β-CD/metal ion system. Detailed investigations were conducted in order to elucidate a plausible initiation mechanism of this polymerization.

A NEW TYPE GRIGNARD REAGENT DERIVED FROM ETHYL-ALPHA-PHENYLSULFINYLACETATE AND ETHYLMAGNESIUM HALIDES

Bei der Behandlung mit den Grignardverbindungen (II) entstehen aus dem Sulfoxidketon (I) die Grignardverbindungen (III), die mit weiterem Grignardreagens zu den Carbinolen (IV) reagieren.