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Irie Laboratory
Kumamoto Univ.
publication:
発表論文
Asymmetric Synthesis of Axially Chiral Benzocarbazole Derivatives based on Catalytic Enantioselective Hydroarylation of Alkynes
S. Arae, S. Beppu, T. Kawatsu, K. Igawa, K. Tomooka, R. Irie*
Org. Lett. 2018, 20, 4796-4800.
A new synthetic approach to novel axially chiral benzocarbazole derivatives based on the highly enantioselective intramolecular hydroarylation (94–96% ee) of linked alkyne–indole systems by using the prevalent chiral base catalyst, cinchonidine or cinchonine, under unprecedented transition-metal-free conditions is described. The process is considered to involve chiral base catalysis for enantioselective transformation of the alkyne part to a reaction intermediate with an axially chiral vinylidene o-quinone methide (VQM) functionality, which subsequently effects stereospecific cyclization with the tethered indole moiety.
Stereoselective Intramolecular Dearomatizative [4+2]
Cycloaddition of Linked Ethynylnaphthol-benzofuran Systems
S. Beppu, S. Arae, M. Furusawa, K. Arita, H. Fujimoto, M. Sumimoto, T. Imahori,
K. Igawa, K. Tomooka, R. Irie*
Eur. J. Org. Chem. 2017, 6914-6918.
A base‐catalyzed stereoselective intramolecular dearomatizative [4+2] cycloaddition of o‐phenylene‐linked ethynylnaphthol–benzofuran systems was explored. In this reaction, we presume the involvement of electrophilic vinylidene o‐quinone methides (4π), which add across the electron‐rich furan double bonds (2π) to produce elaborate, fused oxa‐polyheterocyclic frameworks with consecutive quaternary and tertiary asymmetric carbon atoms as single diastereomers. The catalytic and enantioselective synthesis of these chiral fused polyheterocyclic structures is also feasible with the use of a prevalent cinchonidine or cinchonine chiral base.
Synthesis and Stereochemical Properties of Chiral Hetero[7]helicenes Structured by a Benzodiheterole Ring Core
S. Arae, T. Mori, T. Kawatsu, D. Ueda, Y. Shigeta, N. Hamamoto, H. Fujimoto, M. Sumimoto, T. Imahori, K. Igawa, K. Tomooka, T. Punniyamurthy, R. Irie*
Chem. Lett. 2017, 46, 1214-1216.
A new hetero[7]helicene 1NN structured by a diaza-benzodiheterole (pyrroloindole) ring core was successfully synthesized by catalytic domino cyclodehydrogenation with Pd(OAc)2 and O2 as the key step. Significantly, 1NNwas stereochemically stable at room temperature and could be subjected to optical resolution by chiral HPLC. Furthermore, kinetic analysis of 1NN and DFT calculations on its variants revealed that the stereochemical stability of the benzodiheterole-based helicenes was highly dependent on not only the heteroaromatic ring component but also the N-substituent of the pyrrole ring unit.
Katsuki Catalysts for Asymmetric Oxidation: Design Concepts, Serendipities for Breakthroughs, and Applications
R. Irie*, T. Uchida*, K. Matsumoto*
Chem. Lett. 2015, 44, 1268-1283.
The late Emeritus Professor Tsutomu Katsuki, who was leading the field of catalytic asymmetric oxidation worldwide, suddenly passed away on October 30, 2014. Here we wish to commemorate him by highlighting his representative research works particularly on his unique catalytic systems for asymmetric alkene epoxidation, sulfoxidation, alcohol oxidation, oxidative coupling reactions with a personal view and memory.
Synthesis, Stereochemical Characteristics, and Coordination Behavior of 2,2'-Binaphthyl-1,1'-Biisoquinoline as a New Axially Chiral Bidentate Ligand
T. Kawatsu, H. Tokushima, Y. Takedomi, T. Imahori, K. Igawa, K. Tomooka, R. Irie*
ARKIVOC, 2015, 4, 161-175.
We describe the synthesis, stereochemical characteristics, and coordination behavior of 2,2’binaphtyl-1,1’-biisoquinoline (BINIQ), a new axially chiral bidentate ligand. BINIQ was obtained in a racemic form by the diastereoselective Ullmann coupling of 1-(2-iodonaphthalen1-yl)isoquinoline, which was prepared by the regioselective C-H iodination of 1-(1naphthyl)isoquinoline. BINIQ has three chiral biaryl axes α and γ at the two naphthylisoquinoline and β at the 2,2’-binaphthyl sites and their relative configuration (αRa*,βRa*, γRa*) in solid state was confirmed by X-ray diffraction analysis. The naphthyl-isoquinoline axes α and γ were proven rigid enough in solution to allow for optical resolution by a chiral HPLC method and a solution of the optically pure BINIQ (>98% ee) in chloroform-d did not result in racemization while standing at room temperature for 24 h. On the other hand, the 2,2’-binaphthyl axis is stereochemically labile and readily alternates between βRa and βSa at room temperature. Accordingly, (αRa*,βRa*,γRa*)- and (αRa*,βSa*,γRa*)-BINIQ are in equilibrium in solution with the former stereoisomer being dominant, though the latter is suitable as a bidentate ligand. Notably, this dynamic stereochemical behavior enabled BINIQ to readily give the relative configuration (αRa*,βSa*,γRa*) upon coordination to a copper(I) ion at room temperature.
Synthesis, Structure, and Spin Equilibrium Properties of [Fe(III)X2L](BPh4)･solvents (X = 1-Methylimidazole and Imidazole; L = N,N'-Bis(3-Ethoxycarbonylsalicylidene)ethylenediamine)
T. Fujinami, D. Hamada, N. Matsumoto*, Y. Sunatsuki, R. Irie
Inorg. Chim. Acta. 2015, 430, 239-244.
Two iron(III) complexes [FeIIIX2L]BPh4⋅solvents (X = 1-Meim (1), Him (2)) were synthesized and the crystal structures were determined, where H2L = N, N’-bis(3-ethoxycarbonylsalicylidene)ethylenediamine, 1-Meim = 1-methylimidazole, Him = imidazole, BPh4− = tetraphenylborate. FeIII ion has an octahedral coordination environment by N2O2 donor atoms of equatorial L2− and N2 donor atoms of axial imidazoles. Complex 1 is described as isolated molecule, while complex 2 has a hydrogen-bonded cyclic dimer structure constructed by hydrogen-bond between imidazole group and ethoxycarbonyl oxygen via ethanol. Complex 1 is in a high-spin (S = 5/2) state over the whole temperature region 5–300 K, while complex 2 showed a gradual complete spin equilibrium between high and low-spin states at T1/2 = 192 K.
ジインおよびエンイン系のドミノ環化反応による縮合ヘテロ多環式化合物合成の新手法
入江 亮*, 古澤 将樹, 有田 光佑, 井川 和宣, 友岡 克彦
有機合成化学協会誌, 2014, 72, 1131-1142.
Oxa-heterocyclic compounds such as benzofurans, chromenes, and chromanes constitute a diverse array of biologically active materials. Furthermore, extended π-conjugated systems, in which oxa-heteroaromatic and benzene rings are condensed alternately, have been exploited as components of photoelectronic devices. Thus, the development of efficient synthetic approaches toward these valuable classes of heterocycles has been pursued. Among those precedented heterocyclization methods, domino cyclodehydrogenation and cycloisomerization reactions are highly attractive as they could produce elaborate heterocyclic frameworks from readily available starting materials in an atom-efficient manner. Herein, we wish to report the novel multimode domino ring-forming reactions of o-phenylenediyne-linked bis(arenol)s (aromatic diyne systems) and its analogous aromatic enyne systems to provide unique fused oxa-heterocycles, which are otherwise difficult to synthesize.
Base-catalyzed Schmittel Cycloisomerization of o-Phenylenediyne-linked Bis(arenol)s to Indeno[1,2-c]chromenes
F. Masaki, K. Arita, T. Imahori, K. Igawa, K. Tomooka, R. Irie*
Tetrahedron Lett. 2013, 54, 7107-7110.
We describe the transition metal-free base-catalyzed Schmittel cycloisomerization reactions of o-phenylene-linked bis(arenol)s to indeno[1,2-c]chromene derivatives through prototropic rearrangement (tautomerization) to a putative vinylidene o-quinone methide intermediate with an enyne-allene system followed by a formal inverse-electron-demand hetero Diels–Alder cycloaddition. The preliminary results on catalytic asymmetric cycloisomerization with chiral bases are also disclosed.
Palladium-catalyzed Tandem Cyclodehydrogenation of o-Phenylenediyne-linked Bis(arenol)s to Produce Benzodifuran-containing Condensed Heteroaromatic Ring Systems
F. Masaki, T. Imahori, K. Igawa, K. Tomooka, R. Irie*
Chem. Lett. 2013, 42, 1134-1136.
o-Phenylenediyne-linked bis(arenol) derivatives underwent catalytic cyclodehydrogenation with Pd(OAc)2 and molecular oxygen in DMSO to produce benzodifuran-containing condensed heteroaromatic ring systems, via the formation of two C–O and one C–C bonds in a tandem fashion. Remarkably, the present cycloaromatization proceeded efficiently in the presence of aqueous NaOH and MS 3A to provide the desired heterocycles in moderate-to-high yields.
Synthesis and Stereochemical Behavior of a New Chiral Oxa[7]heterohelicene
R. Irie*, A. Tanoue, S. Urakawa, T. Imahori, K. Igawa, T. atsumoto, K. Tomooka, S. Kikuta, T. Uchida, T. Katsuki
Chem. Lett. 2011, 40, 1343-1345.
A new chiral oxa[7]heterohelicene 1b was synthesized by catalytic aerobic-oxidative tandem cyclization of the o-phenylene-linked bis(2-naphthol) derivative 3 with palladium acetate in dimethyl sulfoxide. Optical resolution of 1b was possible on chiral HPLC, but it was found stereochemically rather unstable at ambient temperature. Kinetic analysis and DFT calculation for the dynamics of racemization of 1b were also disclosed.
DOI: 10.1246/cl.130411
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