Takeru Torigoe 교수

Highly enantioselective cycloisomerization of N-methylanilines, bearing o-alkenyl groups, into indolines is established. An iridium catalyst bearing a bidentate chiral diphosphine effectively promotes the intramolecular addition of the C(sp³ )-H bond across a carbon-carbon double bond in a highly enantioselective fashion. The reaction gives indolines bearing a quaternary stereogenic carbon center at the 3-position. The reaction mechanism involves rate-determining oxidative addition of

New ligands for the iridium-catalyzed C(sp³ )-H borylation of aliphatic compounds were established. In sharp contrast to 6-methyl-2,2'-bipyridine and 6-isobutyl-2,2'-bipyridine, 2,2'-bipyridine and 1,10-phenanthroline derivatives bearing a hydrosilylmethyl group (which would give a thermally stable NNSi pincer complex) served as suitable ligands for the reaction. Among them, a phenanthroline-based NNSi pincer ligand was shown to be an excellent ligand, and various aliphatic compounds

A conversion of trimethylsilylalkanes into the corresponding alcohols is established based on an iridium-catalyzed, chemoselective C(sp³)-H borylation of the methyl group on silicon. The (borylmethyl)silyl group formed by C(sp³)-H borylation is treated with H₂O₂/NaOH, and the resulting (hydroxymethyl)silyl group is converted into a hydroxyl group by Brook rearrangement, followed by oxidation of the resulting methoxysilyl group under Tamao conditions. A

Abstract Catalytic hydroalkylation of an alkyne with methyl ether was accomplished. Intramolecular addition of the C−H bond of a methoxy group in 1‐methoxy‐2‐(arylethynyl)benzenes across a carbon–carbon triple bond took place efficiently either in toluene at 110 °C or in p ‐xylene at 135 °C in the presence of an iridium catalyst. The initial 5‐exo cyclization products underwent double‐bond migration during the reaction to give 3‐(arylmethyl)benzofurans in high yields.

Site-selective C(sp3)–H alkylation of 2-methylanilinium salts via radical intermediates was developed. The anionic decatungstate photocatalyst ([W10O32]4–) interacts with the ammonium group of the substrate through electrostatic interaction and selectively abstracts a hydrogen atom from the proximal benzylic carbon atom under UV irradiation. A variety of 2-methylanilinium salts reacted with electron-deficient alkenes. The alkylated product was successfully converted into an aryl iodide via cleav

The decatungstate photocatalyst [W₁₀O₃₂]^4- efficiently promoted the C(sp³)-H alkylation of the trifluoroacetic acid salt of valine methyl ester (H-Val-OMe·TFA) with electron-deficient alkenes under UV irradiation. The electrostatic interaction between the cationic ammonium group (⁺NH₃) of the main chain and anionic [W₁₀O₃₂]^4- played an important role in this reaction. The influence of various prote

Abstract Highly enantioselective cycloisomerization of N ‐methylanilines, bearing o ‐alkenyl groups, into indolines is established. An iridium catalyst bearing a bidentate chiral diphosphine effectively promotes the intramolecular addition of the C(sp 3 )−H bond across a carbon–carbon double bond in a highly enantioselective fashion. The reaction gives indolines bearing a quaternary stereogenic carbon center at the 3‐position. The reaction mechanism involves rate‐determining oxidative addition o

Abstract New ligands for the iridium‐catalyzed C(sp 3 )−H borylation of aliphatic compounds were established. In sharp contrast to 6‐methyl‐2,2′‐bipyridine and 6‐isobutyl‐2,2′‐bipyridine, 2,2′‐bipyridine and 1,10‐phenanthroline derivatives bearing a hydrosilylmethyl group (which would give a thermally stable NNSi pincer complex) served as suitable ligands for the reaction. Among them, a phenanthroline‐based NNSi pincer ligand was shown to be an excellent ligand, and various aliphatic compounds w

Boronic acid synthesis primarily involves the introduction of boronyl groups. However, an alternative route that involves the functionalization of boronic acids has not received much attention. This study describes the catalytic C(sp³)-H alkylation of <i>ortho</i>-tolylboronic acids utilizing the interaction between a free boronyl group [-B(OH)₂] and a decatungstate photocatalyst [W₁₀O₃₂]^4-. The boronyl groups of the alkylated products could

Abstract The 5‐ammonium‐4,4‐dimethylvaleryl (Amv) group was generated by conversion of acryloyl group through decatungstate‐catalyzed addition of C(sp 3 )−H bond of i ‐BuNH 2 ⋅HCl under the irradiation of UV light (365 nm or 405 nm). Treatment of Amv‐protected alcohols and anilines with aqueous Na 2 CO 3 promoted the efficient deprotection of Amv. This is a unique method for the efficient removal of acryloyl groups from phenols, alcohols, and anilines. The selective removal of acryloyl groups th

Iridium catalysts bearing LLX-type PNSi tridentate ligands (Ir/PNSi catalysts) were developed as new effective catalysts for the C(sp³)-H borylation of alkanes and alkyl groups that do not have directing groups. The Ir/PNSi catalysts were prepared in situ from [Ir(OMe)(cod)]₂ and 8-diarylphosphino-2-[(di-tert-butylhydrosilyl)methyl]quinolines, which are readily synthesized from commercially available 8-bromo-2-methylquinoline. The Ir/PNSi catalyst exhibited higher chemosele

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Abstract Following a one‐pot intramolecular hydroalkylation double‐bond migration sequence various 1‐methoxy‐2‐(arylethynyl)benzene derivatives are transformed into benzofurans.

Abstract Iridium catalysts bearing LLX‐type PNSi tridentate ligands (Ir/PNSi catalysts) were developed as new effective catalysts for the C(sp 3 )–H borylation of alkanes and alkyl groups that do not have directing groups. The Ir/PNSi catalysts were prepared in situ from [Ir(OMe)(cod)] 2 and 8‐diarylphosphino‐2‐[(di‐ tert ‐butylhydrosilyl)methyl]quinolines, which are readily synthesized from commercially available 8‐bromo‐2‐methylquinoline. The Ir/PNSi catalyst exhibited higher chemoselectivity