100461-75-4

Upstream product

• 22955-77-7 methyl 1-indanone-2-carboxylate 
• 119785-62-5 (p-chlorophenyl)ethylmethylsulfonium perchlorate 
• 100569-75-3 ethylmethylphenylsulfonium perchlorate 

Relevant academic research and scientific papers

Asymmetric Induction in the Alkylation of Enolate Anion with the Optically Active Selenium Ions

Alkylation of the enolate anion of 2-methoxycarbonyl-1-indanone with optically active dialkylphenyl selenonium salt resulted in the formation of optically active C-alkylated products.Absolute configuration of the optically active selenonium ion was estimated on tthe basis of the asymmetriic alkylation and CD spectra.

Alkylation of Several Nucleophiles with Alkylsulfonium Salts

The reactions of dialkylphenylsulfonium salts (1) with several nucleophiles such as phenols, amine, enolate ion and thiolate ions, have been investigated.The relative reactivities of the alkyl groups of sulfonium salts for the phenolate ion (hard nucleophile) were as follows; Me:Et:i-Pr = 1.0:1.34:3.44.In the alkylation of the p-toluenethiolate ion (soft nucleophile) with 1, the opposite reactivity (Me:Et:i-Pr = 1.0:0.22:0.03) was found.When a sulfonium salt (1e) having an optically active (S)-s-butyl group was reacted with a phenolate ion, an optically active (R)-s-butyl phenyl ether was obtained with an inversion of the configuration at the chiral carbon atom.A reaction mechanism via a sulfurane intermediate is proposed for the alkylation of the phenolate ion with alkylsulfonium salts.The relative reactivities for the alkylation of several nucleophiles with dialkyl-phenylselenonium salts (12) were also investigated.

Asymmetric Alkylation of β-Keto Esters with Optically Active Sulfonium Salts

Alkylation of the cyclic β-keto ester2-(methoxycarbonyl)-1-indanone (2) with racemic alkylsulfonium salts 1a-h gave 2-alkylindanones 3 and 4 in 60-96percent yields.The relative reactivities of the alkyl substituents of aryldialkylsulfonium salts 1e and 1f were quite different from those in SN2 alkylations.Asymmetric induction occured upon alkylation of 2 with optically active sulfonium salts. (R)-2-Ethyl-2-(methoxycarbonyl)cyclohexanone (11) was obtained in up to 16percent ee by alkylation of the enolate ion of 2-(methoxycarbonyl)cyclohexanone (9) with optically active (R)-(+)-(p-chlorophenyl)ethylmethylsulfonium d-10-camphorsulfonate (1k).Alkylation of the enolate ion of 2 with sulfonium salts containing optically active alkyl groups afforded C-alkylated products with inversion of configuration at the asymmetric alkyl carbon atom.These alkylations appear to proceed via an S-O sulfurane intermediate or a tight ion pair with subsequent stereoselective alkyl migration to the enolate.

NOVEL ASYMMETRIC ALKYLATION OF CYCLIC β-KETO ESTERS WITH OPTICALLY ACTIVE SULFONIUM SALTS

A new asymmetric alkylation of cyclic β-keto esters with optically active sulfonium salts, which are easily prepared by optical resolution methods, has been investigated.Relative reactivities for alkyl substituents are found to be quite different from tho