論文 2008


▼Pyridinium 1,1'-Binaphthyl-2,2'-disulfonates as Highly Effective Chiral Bronsted Acid-Base Combined Salt Catalysts for Enantioselective Mannich-Type Reaction


Manabu Hatano

Toshikatsu Maki

Katsuhiko Moriyama

Manabu Arinobe

Kazuaki Ishihara*

 

J. Am. Chem. Soc. 2008, 130, 16858-16860.

DOI: 10.1021/ja806875c

 

We have established, for the first time, a practical synthesis of chiral 1,1'-binaphthyl-2,2'-disulfonic acid (BINSA, 1) from inexpensive BINOL. An efficient enantioselective catalysis in the Mannich-type reactions of diketones and ketoester equivalents with aldimines was developed using chiral 1-achiral 2,6-diarylpyridine (2) combined salts, which acted as convenient chiral tailor-made Bronsted acid-base organocatalysts in situ.

▼酸・塩基複合塩を鍵とする高機能触媒の設計および高選択的合成法の開拓


坂倉彰*

 

有機合成化学協会誌, 2008, 66(10), 942-952.

▼Chiral Lithium Salts of Phosphoric Acids as Lewis Acid-Base Conjugate Catalysts for the Enantioselective Cyanosilylation of Ketones


Manabu Hatano

Takumi Ikeno

Tokihiko Matsumura

Shinobu Torii

Kazuaki Ishihara*

 

Adv. Synth. Catal. 2008, 350, 1776-1780.

DOI: 10.1002/adsc.200800314

 

The catalytic enantioselective cyanosilylation of aromatic ketones was developed by using chiral lithium salts of (R)-BINOL- or (S)-BINAM-derived phosphoric acid compounds. In the presence of 10 mol% of chiral conjugate lithium salts, the corresponding tertiary cyanohydrins were obtained in high yields with moderate to high enantioselectivities. This is the first efficient example of asymmetric catalysis using lithium salts of synthetically useful chiral phosphoric acid compounds. A possible catalytic mechanism and transition states are also discussed as a preliminary working hypothesis.

▼Open-Air and Solvent-Free Ester Condensation Catalyzed by Sulfonic Acids

 

Akira Sakakura

Yoshiki Koshikari

Kazuaki Ishihara*

 

Tetrahedron Lett. 2008, 49, 5017-5020.

http://dx.doi.org/10.1016/j.tetlet.2008.06.058

 

Under open-air and solvent-free conditions, catalytic amounts of sulfonic acids efficiently promote ester condensation between an equimolar mixture of carboxylic acids and alcohols. Since the present protocol does not require solvents under open-air conditions, a large amount of esters can be synthesized in a rather small apparatus.

▼Kinetic Resolution of Racemic Carboxylic Acids by an L-Histidine-Derived Sulfonamide-Induced Enantioselective Esterification Reaction

 

Kazuaki Ishihara*

Yuji Kosugi

Shuhei Umemura

Akira Sakakura

 

Org. Lett. 2008, 10, 3191-3194.

DOI: 10.1021/ol801007m

 

The direct and catalytic kinetic resolution of racemic carboxylic acids bearing a Bronsted base such as O-protected α-hydroxy carboxylic acids and N-protected α-amino acids has been accomplished through an L-histidine-derived sulfonamide-induced enantioselective esterification reaction with tert-butyl alcohol for the first time. Highly asymmetric induction [S(kfast/kslow) = up to 56] has been achieved under the equilibrium between a chiral catalyst and two diastereomeric acylammonium salts through an intramolecular hydrogen-bonding interaction.

▼Catalytic Enantioselective Organozinc Addition toward Optically Active Tertiary Alcohol Synthesis

 

Manabu Hatano

Kazuaki Ishihara*

 

Chem. Record 2008, 8, 143-155.

DOI: 10.1002/tcr.20146

 

A highly enantioselective organozinc (R2Zn) addition to a series of aldehydes and ketones was developed based on conjugate Lewis acid-Lewis base catalysis. Optically active secondary and tertiary alcohols were obtained in high yields with high enantioselectivities without Ti(IV) compounds. Bifunctional chiral 3,3-diphosphoryl-BINOL ligands were designed and prepared through a phospho-Fries rearrangement as a key step. On the other hand, bifunctional chiral phosphoramide ligands were designed and prepared from L-valine. Mechanistic studies were performed by X-ray analyses of Zn(II) cluster and chiral ligands, a 31P NMR experiment on Zn(II) complexes, and stoichiometric reactions with some chiral or achiral Zn(II) complexes to propose a transition state assembly that includes monomeric active intermediates.

▼有機金属求核剤の炭素-金属結合活性化を基盤とする酸・塩基触媒システムの開発

 

波多野 学

石原 一彰*

 

有機合成協会誌2008, 66(6), 564-577.

http://dx.doi.org/10.5059/yukigoseikyokaishi.66.564

 

For synthesis of secondary and tertiary alcohols, practical carbon-carbon bond forming reactions between organometallic reagents and carbonyl compounds have been developed over a century since the discovery of Grignard reaction in 1900. Traditional organometallic reagents (i.e. Li, Mg, Si, Cu, and Zn reagents) should involve some fundamental functions, such as alkylating reagents, Lewis acids, and Bronsted bases. Thus, in principle, the efficiency of the nucleophilic addition should significantly increase if a carbon-metal bond in organometallic reagents can be activated by Lewis base catalysts and the substrates can be activated by native Lewis acid function of organometallic reagents. We report here that the highly efficient catalytic carbon-carbon bond forming reactions via carbon-metal bond activation in organometallic reagents using simple metal salt catalysts. A variety of acid-base promoting catalytic reactions, such as Grignard reaction, organozinc addition, 1,4-addition of organocopper reagents, trimethylsilylcyanation, and Mukaiyama aldol reaction, were achieved toward the efficient asymmetric catalyses.

▼Asymmetric Intramolecular Cannizzaro Reaction of Anhydrous Phenylglyoxal

 

Kazuaki Ishihara*

Takayuki Yano

Makoto Fushimi

 

J. Fluorine Chem. 2008, 129, 994-997.

http://dx.doi.org/10.1016/j.jfluchem.2008.04.008

 

Double asymmetric induction was achieved in the reaction of anhydrous phenylglyoxal with d-(+)-menthol promoted by a (S,S)-t-BuBox・copper(II) hexafluoroantimonate complex.

▼Convergent Total Syntheses of Fluvibactin and Vibriobactin Using Molybdenum(VI) Oxide-Catalyzed Dehydrative Cyclization as a Key Step

 

Akira Sakakura

Shuhei Umemura

Kazuaki Ishihara*

 

Chem. Commun. 2008, 3561-3563.

DOI: 10.1039/B805880F

 

Efficient total syntheses of fluvibactin and vibriobactin have been achieved via molybdenum(VI) oxide-catalyzed dehydrative cyclization, Sb(OEt)3-catalyzed ester-amide transformation, and WSCI and HOAt-promoted dehydrative amide formation.

▼Organocatalytic Enantioselective Diels-Alder Reaction of Dienes with α-(N,N-Diacylamino)acroleins

 

Kazuaki Ishihara*

Kazuhiko Nakano

Matsujiro Akakura

 

Org. Lett. 2008, 10(13), 2893-2896.

DOI: 10.1021/ol8011277

 

Catalytic and highly enantioselective Diels-Alder reaction of cyclic and acyclic dienes with α-phthalimidoacroleins provides cyclic α-quaternary α-amino acid precursors. The conformationally flexible chiral ammonium salt of H-L-Phe-L-Leu-N(CH2CH2)2-reduced triamine with pentafluorobenzensulfonic acid is very effective as an asymmetric catalyst for the Diels-Alder reaction.

▼Rate-Accelerating Effect by the Neighboring-Group Participation of Protecting Groups in the Dehydrative Cyclization of 1,3,5-Triketones

 

Akira Sakakura

Hitoshi Watanabe

Kazuaki Ishihara*

 

Org. Lett. 2008, 10, 2569-2572.

DOI: 10.1021/ol800860p

 

Neighboring-group participation of an acyl protecting group efficiently promotes the Bronsted acid-catalyzed dehydrative cyclization of 1,3,5-triketones to γ-pyrones, whereas a bulky silyloxy group in the β-position retards the cyclization. This reaction provides an efficient synthetic route for a common intermediate for the synthesis of γ-pyrone-containing bioactive natural products.

▼Catalytic Enantioselective [2 + 4] and [2 + 2] Cycloaddition Reactions with Propiolamides

 

Kazuaki Ishihara*

Makoto Fushimi

 

J. Am. Chem. Soc. 2008, 130(24), 7532-7533.

DOI: 10.1021/ja8015318

 

We report here the catalytic and highly enantioselective [2 + 4] and [2 + 2] cycloaddition reactions of electron-rich dienes or silyl enol ethers with electron-deficient propiolamide derivatives induced by copper(II)-3-(2-naphthyl)-L-alanine amide complex.

▼Zwitterionic Salts as Mild Organocatalysts for Transesterification

 

Kazuaki Ishihara*

Masatoshi Niwa

Yuji Kosugi

 

Org. Lett. 2008, 10, 2187-2190.

DOI: 10.1021/ol8005979

 

The exothermic reaction of 3,5-bis(trifluoromethyl)phenyl or 4-nitrophenyl isothiocyanate with 4-pyrrolidinopyridine (PPY) gave the corresponding arylaminothiocarbonylpyridinium salts in quantitative yields. These novel zwitterionic salts were effective as organocatalysts for the transesterification reaction of an equimolar mixture of methyl carboxylates and alcohols in hydrocarbons such as heptane and octane under azeotropic reflux conditions with the removal of methanol. In sharp contrast, PPY was inert as a catalyst under the same reaction conditions.

▼Recent Progress in the Catalytic Synthesis of Tertiary Alcohols from Ketones with Organometallic Reagents

 

Manabu Hatano

Kazuaki Ishihara*

 

Synthesis 2008, 1647-1675.

DOI: 10.1055/s-2008-1067046

 

Efficient tertiary alcohol synthesis is currently one of the most rapidly advancing fields in organic chemistry, and recent powerful catalytic methodologies can provide versatile tertiary alcohols, even with enantioselective properties. This review summarizes work on the highly efficient catalytic synthesis of tertiary alcohols from ketones and organometallic reagents. New trends in the catalytic synthesis of tertiary alcohols, including functionalized ones, such as tertiary cyanohydrins and tertiary aldols, are examined from the frontier viewpoints that use typical or transition-metal catalysts, organocatalysts, and metal ate complexes, among others.

▼Selective Synthesis of Cyclic Phosphoric Acid Derivatives Through Oxorhenium(VII)-Catalyzed Dehydrative Condansation of Phosphoric Acid Alcohols

 

Akira Sakakura

Masayuki Sakuma

Mikimoto Katsukawa

Kazuaki Ishihara*

 

Heterocycles 2008, 76, 657-665.

DOI: 10.3987/COM-08-S(N)58

 

The selective synthesis of phosphoric acid diesters has been achieved through the direct catalytic dehydrative condensation of phosphoric acid with two equivalents of alcohols. The present method works especially well for the synthesis of cyclic phosphoric acid diesters. The combination of perrhenic acid and N-methylbenzylamine efficiently catalyzes the dehydrative condensation of phosphoric acid with equimolar amounts of diols to give cyclic phosphoric acid diesters in excellent yields.

▼Enantioselective Alkynylation to Aldimines Catalyzed by Chiral 2,2’-Di(2-Aminoaryloxy)-1,1’-Binaphthyl-Copper(I) Complexes

 

Manabu Hatano

Takafumi Asai

Kazuaki Ishihara*

 

Tetrahedron Lett. 2008, 49, 379-382.

http://dx.doi.org/10.1016/j.tetlet.2007.11.032

 

The enantioselective alkynylation of aldimines with terminal acetylenes catalyzed by chiral Cu(I) complexes with (R)-2,2’-di(2-aminoaryloxy)-1,1’-binaphthyl ligands (7) was examined. Chiral C2-symmetric N,N-ligands 7, which have primary aniline moieties, were readily prepared from inexpensive (R)-1,1’-binaphthol (BINOL) as a chiral source. In particular, the reaction of N-benzylidenebenzeneamine 1a with phenylacetylene 2a proceeded smoothly in the presence of 5 mol % of (CuOTf)2・C6H5CH3 and 10 mol % of (R)-7d at room temperature for 24 h, and the corresponding propargylamine 3a was obtained with up to 82% ee.

Recruit

ポスドク及び大学院生を募集中です。

当研究室では学部生、大学院生の研究室見学を随時受け付けております。

希望者は、石原教授までメールでお問い合わせ下さい。

 

Postdoctoral and graduate students is being recruited.In our laboratory will be accepted at any time undergraduate, graduate student visits to laboratories.Those who wish, please contact us by e-mail to Professor Ishihara.

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ISHIHARA GROUP

名古屋大学

大学院工学研究科 有機・高分子化学専攻(工学部 化学生命工学科)
有機化学講座

触媒有機合成学研究グループ

〒464-8603 名古屋市千種区不老町

B2-3(611)

 

Laboratory of Catalysis in Organic Synthesis, Research Group of Molecular Chemistry, Graduate Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering (Undergraduate Department of Chemistry and Biotechnology, School of Engineering), Nagoya University

B2-3(611), Furo-cho, Chikusa, Nagoya 464-8603, Japan