Tsuyoshi Satoh

Magnesium alkylidene carbenoids: Generation from 1-halovinyl sulfoxides with Grignard reagents and studies on their property, mechanism, and some synthetic uses

Abstract Magnesium alkylidene carbenoids were generated from 1-halovinyl sulfoxides, derived from ketones and aryl halomethyl sulfoxide, through the ligand exchange reaction of sulfoxides with Grignard reagents. The generated magnesium alkylidene carbenoids were found to be stable at −78 °C for over 30 min. The carbenoids reacted with aldehydes to give the adducts in moderate yields; however, they were found to be relatively unreactive to usual electrophiles. The generated magnesium alkylidene carbenoid exists in equilibrium between an α-halo alkenyl Grignard reagent and an alkylidene carbene-magnesium halide complex. Halogen exchange and geometrical isomerization of the alkylidene carbenoids were observed. 1-Chlorovinyl sulfoxides reacted with excess aryl Grignard reagents to give alkenyl Grignard reagents having an aryl group. These Grignard reagents reacted with several electrophiles to give tetra-substituted olefins in moderate to good yields.

Autotrophic carbon dioxide fixation in Acidianus brierleyi

The autotrophic CO2 fixation pathway inAcidianus brierleyi, a facultatively anaerobic thermoacidophilic archaebacterium, was investigated by measuring enzymatic activities from autotrophic, mixotrophic, and heterotrophic cultures. Contrary to the published report that the reductive tricarboxylic acid cycle operates inA. brierleyi, the enzymatic activity of ATP:citrate lyase, the key enzyme of the cycle, was not detected. Instead, activities of acetyl-CoA carboxylase and propionyl-CoA carboxylase, key enzymes of the 3-hydroxypropionate cycle, were detected only whenA. brierleyi was growing autotrophically. We conclude that a modified 3-hydroxypropionate pathway operates inA. brierleyi.

The practical procedure for a preparation of 1-chloroalkyl p-tolyl sulfoxides in high optically active form: A very short synthesis of optically active disparlure

Abstract A chlorination of optically active alkyl p-tolyl sulfoxides with N-chlorosuccinimide in dichloromethane in the presence of potassium carbonate afforded optically active 1-chloroalkyl p-tolyl sulfoxides in 87–94% ee (88–94% chemical yields). The optically active chloroalkyl sulfoxide was applied to a synthesis of optically active (+)-disparlure.

Generation of oxiranyllithiums and oxiranyl Grignard reagents having a carbanion-destabilizing group from sulfinyloxiranes: Their property and an application to asymmetric synthesis of epoxides and alcohols

Abstract The first generation of oxiranyllithiums and oxiranyl Grignard reagents having a carbanion-destabilizing group (alkyl group) was realized from sulfinyloxiranes via the ligand exchange reaction of sulfoxides with tert-butyllithium or ethylmagnesium chloride in THF at −80 to −100°C. The generated oxiranyllithiums were found to be very unstable; however, these anions reacted with several electrophiles to give epoxides in up to 86% yield. The oxiranyl Grignard reagents were found to be more stable and much less reactive than the oxiranyllithiums. The reactivities of the oxiranyllithiums having several alkyl groups were investigated. As an application of the method, optically active tri- and tetra-substituted epoxides and alcohols were synthesized from optically active chloromethyl p-tolyl sulfoxide via the oxiranyllithiums.

Cross-coupling of nonstabilized aziridinylmagnesiums with alkylhalides catalyzed by Cu(I) iodide: a new synthesis of amines bearing a quaternary chiral center and an asymmetric synthesis of both enantiomers of the amines from one chiral starting material

Treatment of sulfinylaziridines, which were synthesized from 1-chloroalkyl p-tolyl sulfoxides and imines, with ethylmagnesium bromide gave nonstabilized aziridinylmagnesiums by a sulfoxide-magnesium exchange reaction. The cross-coupling of the aziridinylmagnesiums with various kinds of alkylhalides was realized in high yields by using Cu(I) iodide as a catalyst, and the reaction was found to be stereospecific. The coupling products were hydrogenated with Pd(OH)2 in alcohol to give the amines bearing a quaternary chiral center in quantitative yields. Synthesis of both enantiomers of the amines bearing a quaternary chiral center was realized starting from optically active (R)-chloromethyl p-tolyl sulfoxide in good overall yields with perfect asymmetric induction.

A new method for synthesis of allenes, including an optically active form, from aldehydes and alkenyl aryl sulfoxides by sulfoxide-metal exchange as the key reaction and an application to a total synthesis of male bean weevil sex attractant

Abstract The sulfoxide–metal exchange reaction of β-acetoxy sulfoxides or β-mesyloxy sulfoxides, which were derived from alkenyl aryl sulfoxides and aldehydes in two steps, with a Grignard reagent or alkyllithium at low temperature gave allenes in good yields. Optically active allenes were synthesized starting from optically active 2-substituted ethenyl p-tolyl sulfoxides. A synthesis of (−)-methyl (E)-2,4,5-tetradecatrienoate, a male bean weevil sex attractant, was realized by this method.

Stereospecific desulfinylation of sulfinylaziridines with ethylmagnesium bromide: A novel synthesis of (Z)-N-arylaziridines☆

Abstract A novel synthesis of (Z)-N-arylaziridines was realized by the stereospecific desulfinylation of (E)-(N-aryl)sulfinylaziridines which were synthesized from 1-chloroalkyl p-tolyl sulfoxides and N-arylimines in high yields.

A new method for synthesis of allenes, including an optically active form, from aldehydes and alkenyl aryl sulfoxides with carboncarbon bond-formation

Abstract Ligand exchange reaction of β-mesyloxy sulfoxides or β-acetoxy sulfoxides, which were derived from alkenyl aryl sulfoxides and aldehydes in two steps, with n -BuLi or EtMgBr at low temperature gave allenes in good yields. Optically active allenes were synthesized starting from optically active 2-phenylethenyl p -tolyl sulfoxides.

A novel synthesis of epoxides and allylic alcohols from carbonyl compounds through α,β-epoxy sulfoxides

Abstract Treatment of α,β-epoxy sulfoxides, easily prepared from carbonyl compounds with 1 equivalent of n-butyllithium at −100 °C gave the desulfinated epoxides in good yields. The similar α,β-epoxy sulfoxides having arylmethyl group at α-position, on treatment with excess n-butyllithium at −70 °C afforded 3-aryl allylic alcohols.

A novel synthesis of allenes by alkenylation of magnesium alkylidene carbenoids with lithium α-sulfonyl carbanions

Abstract Treatment of magnesium alkylidene carbenoids, which were generated from 1-chlorovinyl p -tolyl sulfoxides with a Grignard reagent by sulfoxide–magnesium exchange, with lithium α-sulfonyl carbanions gave allenes in moderate to good yields. This procedure offers a novel synthetic method for allenes with three-component coupling in relatively short steps.