Shuichi Hayase

Enhanced enantioselectivity and remarkable acceleration on the lipase-catalyzed transesterification using novel ionic liquids

Novel imidazolium salt ionic liquids were prepared derived from polyoxyethylene(10) cetyl sulfate and used as an additive for lipase-catalyzed transesterification in organic solvent; a remarkable enhanced enantioselectivity was obtained when the salt was added in 3 to 10 mol% vs. substrate in the Pseudomonas cepacia lipase-catalyzed transesterification of 1-phenylethanol using vinyl acetate in a diisopropyl ether or hexane solvent system. There was a remarkable acceleration when the lipase was coated with this novel ionic liquid and used as catalyst for transesterification in i-Pr2O or in hexane.

1-Butyl-2,3-dimethylimidazolium tetrafluoroborate: the most desirable ionic liquid solvent for recycling use of enzyme in lipase-catalyzed transesterification using vinyl acetate as acyl donor

Abstract 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate ([bdmim]BF 4 ) was found to be an excellent solvent to realize a lipase-recycling system using vinyl acetate as acyl donor. No accumulation of an acetaldehyde oligomer was observed in this solvent system and it was possible to use the lipase repeatedly 10 times while still maintaining perfect enantioselectivity and high reactivity.

A rational design of phosphonium salt type ionic liquids for ionic liquid coated-lipase catalyzed reaction

A rational design of phosphonium ionic liquid for ionic liquid coated-lipase (IL1-PS)-catalyzed reaction has been investigated, and very rapid transesterification of secondary alcohols accomplished when IL1-PS was used as catalyst in 2-methoxyethoxymethyl(tri-n-butyl)phosphonium bis(trifluoromethanesulfonyl)amide ([P444MEM][NTf2]) as solvent while perfect enantioselectivity was maintaining. Increased Kcat value was suggested to be the most important factor in IL1-PS working the best in [P444MEM][NTf2] solvent.

Design of fulleropyrrolidine derivatives as an acceptor molecule in a thin layer organic solar cell

A systematic study on the design of fulleropyrrolidine derivatives as the acceptor of photovoltaic cells has been carried out using poly(3-hexylthiophene) (P3HT) as the model base polymer. It was found that N-methoxyethoxyethyl-2-(2-methoxyphenyl)fulleropyrrolidine worked as a good acceptor partner with P3HT and a high power conversion efficiency (PCE) (3.44%) was obtained; this is superior to that of the P3HT polymer including methyl [6,6]-phenyl-C61-butylate ([C60]-PCBM) under the same experimental conditions.

Synthesis of Optically Active 2,3-Dihydrobenzofuran Derivatives through a Combination Strategy of Iron(III)-Catalyzed Reaction and Enzymatic Reaction

Synthesis of optically active 2,3-dihydrofuran derivatives has been accomplished through a combination strategy of ferric ion-catalyzed cycloaddition of styrene derivatives with quinones and following lipase-catalyzed enantioselective acylation.

A possible means of realizing a sacrifice-free three component separation of lignocellulose from wood biomass using an amino acid ionic liquid

Lignocellulose materials are potentially valuable resources for transformation into many bio-products. However, because of the difficulty in fractionating them into cellulose, hemicellulose, and lignin by a simple method directly from wood biomass, their economical conversion into high value-added products has been greatly limited. We found that N-methyl-N-(2-methoxyethyl)pyrolidin-1-ium 2,6-diaminohexanoate ([P1ME][Lys]) dissolved lignin very well below 60 °C, but that 80 °C was required for it to dissolve cellulose. Taking advantage of this difference in dissolution ability, direct extraction of lignin from wood biomass has been accomplished under mild conditions without the use of any hazardous reagents. Since lignin acts as the essential glue that binds cellulose and hemicellulose and gives plants their structural integrity, we have achieved the demonstration of the sacrifice-free separation of cellulose, hemicellulose, and lignin from wood biomass (Japanese cedar: Cryptomeria japonica).

Ruthenium-catalysed linear-selective allylic alkylation of allyl acetates

The regioselectivity in the ruthenium-catalysed allylic alkylation of mono substituted allyl acetates with the malonate anion was highly controlled by Ru3(CO)12 with 2-(diphenylphosphino)benzoic acid, and the linear-type alkylated product was obtained.

Automated Electrochemical Assembly of the Protected Potential TMG-chitotriomycin Precursor Based on Rational Optimization of the Carbohydrate Building Block

The anomeric arylthio group and the hydroxyl-protecting groups of thioglycosides were optimized to construct carbohydrate building blocks for automated electrochemical solution-phase synthesis of oligoglucosamines having 1,4-β-glycosidic linkages. The optimization study included density functional theory calculations, measurements of the oxidation potentials, and the trial synthesis of the chitotriose trisaccharide. The automated synthesis of the protected potential N,N,N-trimethyl-d-glucosaminylchitotriomycin precursor was accomplished by using the optimized building block.

TWO-STEP SYNTHESIS OF TRIARYLMETALS (AS, SB, BI) STARTING FROM THE METAL OXIDES AND 2,6-DIMETHOXYBENZENETHIOL

Reported here is a new synthetic method of triarylmetals MAr3 (M = As, Sb, Bi). It is composed of two-step reactions starting from the metal oxides: (1) A reaction of the metal oxide with 2,6-dimethoxybenzenethiol ΦSH [Φ = 2,6-(MeO)2C6H3] in the presence of acid to give the thiolatometals M(SΦ)3, and (2) A reaction of M(SΦ)3 with organolithium reagent LiAr to give MAr3 (Ar = Ph, 4-MeC6H4, 4-Me2NC6H4, Φ). Since ΦSH is odorless and crystalline, most of it can be recovered after the reactions without difficulty for repeated usages. The intermediates M(SΦ)3 are also crystalline and inert against hydrolysis.

1:1 Complexes of dimethyltin dihalides with tris(2,6-dimethoxyphenyl)phosphine oxide, its sulphide, and related compounds

Dimethyltin dihalides Me2SnX2 (X = Cl, Br) only form 1:1 complexes with 2,6-dimethoxyphenylphosphine oxides Φ3PO, PhΦ2PO and Ph2ΦPO (Φ = 2,6-(MeO)2C6H3) even though the ligands are used in excess. 2,6-Dimethoxyphenylphosphine sulphides Φ3PS and PhΦ2PS also form analogous 1:1 complexes, while Ph2ΦPS and Ph3PS do not react. X-Ray crystal structural analysis of Me2SnCl2·OPΦ3 reveals that the tin atom is penta-coordinated in a distorted trigonal bipyramidal arrangement, with a chlorine and two methyl carbon atoms in the equatorial positions and the other chlorine and the Φ3PO oxygen atom in the axial positions.