Naoki Kise

Preparation of Pd(II) enolate complexes and their reactions

Abstract Palladium(II) enolate complexes have been prepared by the reaction of Pd(II)Cl 2 -(PhCN) 2 with trimethylsilyl enol ethers and reacted with CO and ethylene.

Asymmetric synthesis of optically active 2,3-diarylsuccinic acids by oxidative homocoupling of chiral 3-(arylacetyl)-2-oxazolidones

Abstract Oxidative homocoupling of chiral 3-(arylacetyl)-2-oxazolidones 1 was achieved by treatment with DABCO-TiCl4 or DMAP-TiCl4 and afforded the corresponding dimers stereospecifically. The reaction of (4S)- and (4R)-substituted 1 gave (S,S)- and (R,R)-dimers respectively. The obtained dimers were easily transformed to the corresponding 2,3-diaryl succinic acids. This reaction therefore provides a useful method for the synthesis of optically pure 2,3-diarylsuccinic acids. The oxidative coupling was not inhibited by para substitution of an electron donating group on the aryl group. A para-substituted electron withdrawing group and an ortho-substituent, however, hindered the coupling.

ORGANOTHIO GROUPS AS ELECTROAUXILIARIES : ELECTROOXIDATIVE INTER- AND INTRAMOLECULAR CARBON-CARBON BOND FORMATION

Abstract Anodic oxidation of α-organothio ethers results in the cleavage of the carbon-sulfur bond and the introduction of carbon nucleophiles onto the carbon, suggesting the effectiveness of organothio groups as electroauxiliaries.

Electroreductive Intramolecular Coupling of Phthalimides with Aromatic Aldehydes: Application to the Synthesis of Lennoxamine

The electroreductive intramolecular coupling of phthalimides with aromatic aldehydes in the presence of chlorotrimethylsilane and triethylamine led to five-, six-, and seven-membered cyclized products (58-84%). The electroreductive cyclization was applied to the total synthesis of lennoxamine.

Electroreductive intramolecular coupling of γ- and δ-cyanoketones

Abstract Electroreduction of γ- and δ-cyanoketones in i-PrOH gave cyclized products α-hydroxyketones and their dehydroxylated ketones, and this reaction was applied to the synthesis of dihydrojasmone, methyl dihydrojasmonate, and Rosaprostol.

New synthesis of β-amino acids by nucleophilic addition of enolate anions to N-methoxycarbonylimines generated from α-methoxy carbamates1☆

Abstract The nucleophilic addition of enolate anions of alkyl acetates to N-methoxycarbonylimines generated from α-methoxy carbamates gave β-amino acid derivatives ( 3 ) and enantioselective synthesis (72-90%ee) of 3 was achieved by using chiral 2-methyloxazolines instead of acetates.

Electroreductive Coupling of Phthalimides with α,β-Unsaturated Esters: Unusual Rearrangement of Resulting Silyl Ketene Acetals

The electroreductive intramolecular coupling of phthalimides with alpha,beta-unsaturated esters in the presence of chlorotrimethylsilane and subsequent desilylation of resulting silyl ketene acetals with TBAF gave five- and six-membered trans-cyclized products stereospecifically. The silyl ketene acetals were readily rearranged to benzoindole and tetrahydrobenzoquinoline by standing or treatment with a Lewis acid under open-air conditions. The electroreductive intermolecular coupling of N-methylphthalimide with methyl acrylate also proceeded.

Electroreductive intramolecular coupling of 1-indolealkanones.

The electroreduction of 1-indolealkanones in isopropanol gave five-, six-, and seven-membered trans-cyclized products stereospecifically. On the other hand, the electroreduction of 3-methoxycarbonyl-1-indolealkanones afforded mixtures of two diastereomers of the corresponding trans- and cis-cyclized products. The DFT calculations for the radical anions support that the reductive couplings of 1-indolealkanones and 3-methoxycarbonyl-1-indolealkanones proceed through different reaction mechanisms.

Formation and reaction of 2-metalated N-Boc-4,4-dimethyl-1,3-oxazolidines in the presence of (−)-sparteine: new chiral formyl anion equivalents

Abstract Lithiation of N -Boc-4,4-dimethyl-1,3-oxazolidine with s -BuLi and the following reaction with benzaldehyde was carried out in the presence of (−)-sparteine. The reaction was not diastereoselective ( syn : anti =46:54), but each isomer of the adducts was obtained enantioselectively ( syn : 90% ee, anti : 88% ee). Addition of MgBr 2 to the reaction mixture increased the diastereoselectivity to syn : anti =90:10.

Reaction of N-acyl-α-methoxyamines with organozinc reagents. A convenient method for the synthesis of homoallylamines and β-amino esters

The reaction of N-acyl-α-methoxyamines with allyl-, propargyl-, and benzylzinc bromides and Reformatsky reagents proceeds in THF at room temperature. Homoallyl- and homopropargylamines and β-amino esters are synthesized in good yields.