Hokkaido University · 화학
이 교수의 연구실은 전이금속 촉매를 중심으로 한 고도로 선택적인 C–H 기능화 및 탄소-탄소/탄소-질소 결합 형성 반응을 연구하고 있습니다. 특히 이트륨 기반 촉매 시스템을 활용한 알데하이드의 탈카복실화, 알킨과의 선택적 산화적 접합 반응, 그리고 고분자 기반 리간드를 통한 촉매의 고정화 기술 개발에 주력하고 있습니다. 복잡한 유기 분자의 효율적 합성과 촉매의 재사용성을 동시에 확보하는 데 초점을 맞추고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Quinoline is an important scaffold in many natural products, biologically active compounds, and functional materials. The C–H functionalization of quinoline scaffolds by transition metal catalysis provides an efficient method for rapidly obtaining substituted quinolines. This review summarizes recently reported transition-metal-catalyzed site-selective C–H functionalization of quinolines, excluding C2 selective reactions. A review of direct functionalization of quinoline N-oxides at the C8 posit
The catalytic decarbonylation of aldehydes has been developed using commercially available [IrCl(cod)](2) and PPh(3) under mild conditions, and the method could be widely applicable to various substrates with different functionalities.
An iridium N-heterocyclic carbene (NHC) complex, IrCl(cod)(IPr), successfully catalyzed an addition of common aromatic acid chlorides to terminal alkynes to afford (Z)-beta-chloro-alpha,beta-unsaturated ketones regio- and stereoselectively. When the NHC ligand (IPr) was changed to a phosphine (RuPhos), the addition occurred with decarbonylation to give the corresponding (Z)-vinyl chlorides. Furthermore, the former reaction using IrCl(cod)(IPr) can be applied to the catalytic synthesis of 2,5-dis
Covalently bound polystyrene-phosphane hybrids were prepared by a method based on radical emulsion polymerization of styrenes in the presence of a tris(p-vinylphenyl)phosphane cross-linker. These hybrids favor mono-P-ligation to transition-metal complexes and are useful for challenging catalysis, such as Pd-catalyzed CC/CN couplings with unactivated chloroarenes and Ir- or Rh-catalyzed C(sp(3) )H borylations.
An iridium complex successfully catalyzed the annulation of various N-arylcarbamoyl chlorides with internal alkynes to afford 2-quinolones in good to excellent yields. The present reaction is widely applicable to substrates with various functionalities. An amide-iridacycle complex was isolated, and it is likely that such an iridacycle species is a key intermediate in the catalytic reaction.
Semihollow triethynylphosphanes were synthesized and employed as ligands in the gold-catalyzed 8-exo-dig cyclization of acetylene-tethered silyl enol ethers to obtain eight-membered-ring carbocycles (see scheme). The gold–phosphane catalysts promoted either the annulation toward bicyclic structures or the cyclization of acyclic molecules to form nonfused carbocycles. Tf=Trifluoromethylsulfonyl. As a service to our authors and readers, this journal provides supporting information supplied by the
A polystyrene-cross-linking bisphosphine PS-DPPBz was synthesized through radical emulsion copolymerization between 4-t-butylstyrene as a monomer and tetravinylated 1,2-bis(diphenylphosphino)benzene (DPPBz) as a 4-fold cross-linker. The location of the DPPBz bisphosphine moiety at the branching points of the cross-linked network organic polymer allowed controlled bisphosphine monochelation to transition metals under conditions where homogeneous ligands may form bischelated single metal complexes
Iridium complexes show high catalytic activity in intermolecular additions of acid chlorides to terminal alkynes to afford valuable (Z)-β-chloro-α,β-unsaturated ketones. Ligands in the catalytic system play a crucial role in this reaction. An N-heterocyclic carbene (NHC) is an efficient ligand for the addition of aroyl chlorides, while dicyclohexyl(2-methylphenyl)phosphine (PCy(2)(o-Tol)) is indispensable for the reaction of aliphatic acid chlorides. The addition reactions proceed regio- and ste
Herein, we describe a new catalytic approach to accessing aromatic amines from an abundant feedstock, namely phenols. The most reliable catalytic method for converting phenols to aromatic amines uses an activating group, such as a trifluoromethane sulfonyl group. However, this activating group is eliminated as a leaving group during the amination process, resulting in significant waste. Our nickel-catalyzed decarboxylation reaction of aryl carbamates forms aromatic amines with carbon dioxide as
The Ni-catalyzed cross-coupling reaction between aryl fluorides and primary amines was enabled by the 1,2-bis(dicyclohexylphosphino)benzene (DCYPBz) or 1,2-bis(dicyclohexylphosphino)ethane (DCYPE) ligands. Both N-alkyl- and N-aryl-substituted primary amines participated in the selective reaction to form secondary amines. This protocol would potentially be useful for late-stage diversification of fluorinated compounds with complex structures for the synthesis of functionally interesting aniline d
Abstract A silica‐supported tripod triarylphosphane (Silica‐3p‐TPP), containing a triphenylphosphane‐type core tripodally immobilized on the silica surface, allows rhodium‐ and iridium‐catalyzed C( sp 3 )H borylations of amide, urea and alkylpyridine derivatives. The 31 P CP/MAS NMR studies for the coordination behavior of the tripod phosphane towards a rhodium complex indicate efficient site isolation of the each phosphane center, allowing independent mono‐P‐coordination to the metal center. m
Non-activated aryl fluorides reacted with potassium diorganophosphinites through a nucleophilic aromatic substitution (S<sub>N</sub> Ar) reaction. Remarkably, both electron-neutral and electron-rich aryl fluorides participated in the reaction with substantially stabilized anionic P nucleophiles to form the corresponding tertiary phosphine oxides. Quantum chemical calculations suggested a nucleophile-dependent mechanism that involves both concerted and stepwise S<sub>N</sub> Ar reaction pathways.
The polystyrene-cross-linking bisphosphine ligand PS-DPPBz was effective for the Ir-catalyzed reversible acceptorless dehydrogenation/hydrogenation of <i>N-</i>heterocycles. Notably, this protocol is applicable to the dehydrogenation of N<i>-</i>substituted indoline derivatives with various N<i>-</i>substituents with different electronic and steric natures. A reaction pathway involving oxidative addition of an N-adjacent C(sp<sup>3</sup>)-H bond to a bisphosphine-coordinated Ir(I) center is prop
Abstract Cationic gold(I) complexes with hollow‐shaped triethynylphosphine ligands efficiently catalyzed intramolecular [2+2] cycloaddition of 1,9‐enynes to afford cyclobutene‐fused eight‐membered carbocycles that were difficult to synthesize by other catalytic systems. Various 1,9‐enynes with carbon linkers with or without a fused ring underwent efficient [2+2] cycloaddition with 5 mol% of the Au catalyst bearing the triarylmethyl‐end‐capped triethynylphosphine in CH 2 Cl 2 at rt in the presenc
