1-chloroalkyl Phenyl Sulfoxides Research Articles

The First Example of Magnesium Carbenoid 1,3‐CH Insertion Reaction: A Novel Method for Synthesis of Cyclopropanes from 1‐Chloroalkyl Phenyl Sulfoxides in High Yields.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The first example of magnesium carbenoid 1,3-CH insertion reaction: a novel method for synthesis of cyclopropanes from 1-chloroalkyl phenyl sulfoxides in high yields

Treatment of 1-chloroalkyl phenyl sulfoxides having a geminal methyl group or a geminal benzyl group at the 2-position in THF at −78 °C with isopropylmagnesium chloride gave magnesium carbenoids. Carbenoid 1,3-CH insertion reaction of the magnesium carbenoids took place instantaneously to afford cyclopropanes in high to quantitative yields.

Reaction of Magnesium Carbenoids with N‐Lithio Arylamines: A Novel Method for Generation of Non‐Stabilized α‐Amino‐Substituted Carbanions and a New Synthesis of α‐Amino Acid Derivatives.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Generation of Magnesium Carbenoids from 1‐Chloroalkyl Phenyl Sulfoxides with a Grignard Reagent and Applications to Alkylation and Olefin Synthesis.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Reaction of magnesium carbenoids with N-lithio arylamines: a novel method for generation of non-stabilized α-amino-substituted carbanions and a new synthesis of α-amino acid derivatives

Treatment of 1-chloroalkyl phenyl sulfoxides with a Grignard reagent at low temperature afforded magnesium carbenoids in quantitative yields. The magnesium carbenoids were found to be reactive with N-lithio alkylamines and N-lithio arylamines. The reaction with N-lithio alkylamines afforded an olefin, which was derived from dimerization of the magnesium carbenoid, in moderate yield. The reaction with N-lithio arylamines gave the adducts, α-amino-substituted carbanions, in good yields. From these intermediates, a novel synthesis of α-amino acid derivatives and N, N-dialkyl arylamines having a deuterium at the α-position was realized.

Generation of magnesium carbenoids from 1-chloroalkyl phenyl sulfoxides with a Grignard reagent and applications to alkylation and olefin synthesis

Treatment of 1-chloroalkyl phenyl sulfoxides with a Grignard reagent at low temperature gave magnesium carbenoids in quantitative yields. The generated magnesium carbenoids were found to be stable at lower than −60 °C for long periods of time and are reactive with Grignard reagents to give alkylated products. The reaction of the generated magnesium carbenoids with various kinds of lithium α-sulfonyl carbanions gave olefins with carbon–carbon bond-formation in good to high yields. This method offers a good way for the preparation of olefins. The scope and limitations of the above-mentioned reactions are described.

Generation of magnesium carbenoids from 1-chloroalkyl phenyl sulfoxides with a Grignard reagent and applications to alkylation and olefin synthesis

Treatment of 1-chloroalkyl phenyl sulfoxides with a Grignard reagent at low temperature gave magnesium carbenoids in quantitative yields. The generated magnesium carbenoids were found to be stable at lower than −60 °C for long periods of time and are reactive with Grignard reagents to give alkylated products. The reaction of the generated magnesium carbenoids with various kinds of lithium α-sulfonyl carbanions gave olefins with carbon–carbon bond-formation in good to high yields. This method offers a good way for the preparation of olefins. The scope and limitations of the above-mentioned reactions are described. Graphic

Generation of the α-Sulfinyl Carbenoid from α-Chloro Sulfoxides: A New Method for One-Carbon Homologation of Ketones to α-Sulfinyl Ketones

Abstract Treatment of 1-chloroalkyl phenyl sulfoxides with a base gave carbenoids rather than free carbenes. The carbenoids were successfully used in a new method for homologation of ketones to α-sulfinyl ketones. Treatment of the carbanion of chloromethyl phenyl sulfoxide with ketones gave the adducts, α-chloro β-hydroxy sulfoxides, in nearly quantitative yields. The adducts were treated with excess lithium diisopropylamide to give one-carbon homologated α-sulfinyl ketones via α-sulfinyl β-oxido carbenoids in moderate to good yields. This type of reaction was found not to occur with the corresponding sulfones.

A Novel Synthesis of Methylenecyclopropane Spiro-Linked with Cycloalkanes via a Cyclization of Allylic Epoxides and Its Application to a Synthesis of Fused 3-Methylfurans

Abstract Ring closure of allylic epoxides derived from 1-chloroalkyl phenyl sulfoxides and cyclic ketones with lithium diisopropylamide (LDA) in 3-Exo-Tet mode gave spiro-linked methylenecyclopropanes having a hydroxyl group in good yields. Oxidation of these compounds gave ketones, which were then treated with p-toluenesulfonic acid in 1,4-dioxane or DMSO at 100°C to give fused 3-methylfurans in good overall yields. This procedure was applied to a synthesis of menthofuran from 4-methylcyclohexanone.

A novel synthesis of carbocyclic spiro-type methylenecyclopropane derivatives

A novel method is described for the synthesis of carbocyclic spiro-type methylenecyclopropane derivatives via the cyclization of allyl-epoxides, which are readily available from ketones and 1-chloroalkyl phenyl sulfoxides.

Reduction of .BETA.-keto sulfoxides having an alkyl group and a chlorine atom on the .ALPHA.-carbon. A synthesis of (E)-.ALPHA.,.BETA.-epoxy sulfoxides.

Oxidation of the chlorohydrins derived from 1-chloroalkyl phenyl sulfoxides and aldehydes gave the β-keto sulfoxides having an alkyl group and a chlorine atom on the α-carbon. The β-keto sulfoxides were reduced with diisobutylaluminum hydride to afford the syn-chlorohydrins as sole products, which were converted to the (E)-α, β-epoxy sulfoxides.

A novel and stereoselective synthesis of (E)-1-acylbutadienes from 1-chloroalkyl phenyl sulfoxides and 4-(phenylthio)butanal through .ALPHA.,.BETA.-epoxy sulfoxides.

A novel and stereoselective synthesis of (E)-1-acylbutadienes from 1-chloroalkyl phenyl sulfoxides and 4-(phenylthio)butanal through .ALPHA.,.BETA.-epoxy sulfoxides.

A Novel Method of Annulation through α,β-Epoxy Sulfoxides with the Aid of Intramolecular Radical Cyclization

Abstract A novel method of annulation was realized from ketones through α,β-epoxy sulfoxides with the aid of endo-type intramolecular radical cyclization. In these reactions 1-chloroalkyl phenyl sulfoxides having phenylseleno group on an end of the alkyl group acted as synthons of the annulation.

α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. X. An Improved Synthesis of α,β-Unsaturated Carbonyl Compounds from Carbonyl Compounds with Carbon Homologation through α,β-Epoxy Sulfoxides

Abstract Treatment of the α,β-epoxy sulfoxides derived from ketones and chloromethyl phenyl sulfoxide or 1-chloroalkyl phenyl sulfoxides with lithium perchlorate in the presence of tributylphosphine oxide in toluene at 110 °C for about 1–3 h gave α,β-unsaturated aldehydes or α,β-unsaturated ketones in high yields. In contrast to these results, the α,β-epoxy sulfoxides derived from aldehydes did not give the desired α,β-unsaturated ketones. In this case, a sequential treatment of the α,β-epoxy sulfoxides with benzenethiolate and m-chloroperbenzoic acid afforded α-phenylsulfinylated ketones, which were heated in toluene at 110 °C to give the desired enones in good overall yields. The oxidation of the α,β-unsaturated aldehydes obtained by this method gave α,β-unsaturated carboxylic acids in high yields. These procedures afforded a new method for the synthesis of α,β-unsaturated carbonyl compounds, including α,β-unsaturated esters, from carbonyl compounds with carbon homologation.

α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. IV. A Novel Synthesis of α-Acetoxy Ketones from α,β-Epoxy Sulfoxides

Abstract The treatment of α,β-epoxy sulfoxides, prepared from 1-chloroalkyl phenyl sulfoxides with ketones or aldehydes, with cesium acetate in dimethyl sulfoxide in the presence of lead tetraacetate afforded α-acetoxy ketones in moderate to good yields.

α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. III. A Novel Synthesis of α-Amino Ketones and α-Amino Aldehydes by Aminolysis of α,β-Epoxy Sulfoxides

Abstract Aminolysis of α,β-epoxy sulfoxides, easily prepared from 1-chloroalkyl phenyl sulfoxides or chloromethyl phenyl sulfoxide and carbonyl compounds, with alkyl- or arylamines afforded α-amino ketones or α-amino aldehydes in good yields. Treatment of thus obtained α-arylamino ketones with weak Lewis acid led to 2,3-disubstituted indoles.

α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. II. A Novel Synthesis of α-Sulfenylated Ketones and α-Sulfenylated Aldehydes from α,β-Epoxy Sulfoxides

Abstract Treatment of α,β-epoxy sulfoxides, prepared from 1-chloroalkyl phenyl sulfoxides and carbonyl compounds, with various kinds of alkane- or arenethiolates afforded α-sulfenylated ketones in good yields. This method also offered a novel procedure for a synthesis of α-sulfenylated aldehydes.

α,β-Epoxy Sulfoxides as Useful Intermediates in Organic Synthesis. I. A Novel Synthesis of Dialkyl Ketones and a Synthesis of Aldehydes from Ketones by One Carbon Elongation

Abstract Treatment of α,β-epoxy sulfoxides, prepared from 1-chloroalkyl phenyl sulfoxides with ketones or aldehydes, with sodium benzeneselenolate gives dialkyl ketones or aldehydes in good yields under mild conditions. The mechanism of this reaction and an application of this process to a formal total synthesis of dihydrojasmone are described.