박진균 교수

We present a 6-NHC-Cu(I) complex that provides α-substituted allylboronates using allylic aryl ether substrates. The method was discovered by comparison of the chemoselectivities exhibited by complexes 1a, 1b, 2, and 3. We observed that 1a preferentially reacts with electron-rich alkenes over electron-deficient alkenes. Development of an asymmetric method revealed that 1b reacts with both the E and Z isomers to provide the same absolute configuration without showing E-Z isomerization. This stere

A chiral 6-membered annulated N-heterocyclic (6-NHC) copper complex that catalyzes β-borylations with high yield and enantioselectivity was developed. The chiral 6-NHC copper complex is easy to prepare on the gram scale and is very active, showing 10,000 turnovers at 0.01 mol % of catalyst without significant decrease of enantioselectivity and with useful reaction rates.

The catalytic regioselective hydroboration of propargylic alcohols and ethers was investigated using NHC-CuCl. We observe that different NHC-CuCl complexes catalyze hydroborations of propargylic substrates with opposite regioselectivity. A 6-NHC-CuCl complex provides α-selectivity whereas β-selectivity is achieved using a 5-NHC-CuCl complex. The reaction tolerates a wide range of functional groups.

N-Alkynylindoles were divergently cyclized for the synthesis of multifused N-heterocycles. An ortho-aryl palladium species was added to the α position of an ynamine to generate (Z)-6-alkylidene/benzylidene-6H-isoindolo[2,1-a]indoles, while Pt-catalyzed β-addition through π-activation gave 5-alkyl/arylindolo[2,1-a]isoquinolines. Double cyclizations using PdCl₂ and oxidant afforded bright yellow benzo[7,8]indolizino[2,3,4,5-ija]quinolines, the synthesis of which was also demonstrated in

A copper-catalyzed asymmetric allylic boronation (AAB) gives access to syn- and anti-1,2-diols. The method facilitates an iterative strategy for the preparation of polyols, such as the fully differentiated L-ribo-tetrol and protected D-arabino-tetrol. P=protecting group.

Abstract Pd‐catalyzed hydroalkynylations were developed that involve ligand‐enabled regiodivergent addition of an alkyne to an allenamide, giving branched and linear products stereoselectively and facilitated by the neighboring amide group. Regioselectivity was achieved with the use of ( o ‐OMePh) 3 P and BrettPhos, which allowed the functionalization of various alkynes, including steroids, carbohydrates, alkaloids, chiral ligands, and vitamins. Based on the experimental results, it was proposed

Abstract Various imidazolium ionic liquids such as [Bmim]PF 6 , [Bmim]SbF 6 , [Bmim]OTf and [Bmim]BF 4 were screened for recycling an organic catalyst [(5 S )‐5‐benzyl‐2,2,3‐trimethylimidazolidin‐4‐one ( 1 )] for asymmetric Diels–Alder reactions. Good yields and enantioselectivies (up to 85% yield and 93% ee) were obtained from reactions in [Bmim]PF 6 or [Bmim]SbF 6 . However, reactions in [Bmim]OTf or [Bmim]BF 4 gave racemic products in low yields. Isolation of the products by simple extraction

A chiral pyrrolidinylmethanol derivative containing perfluoro-ponytails (5) was prepared from (S)-proline. The use of this perfluoro-substituted amino alcohol in catalytic asymmetric additions of organozinc reagents to aldehydes affords products with high enantioselectivities in both pure hexane and a mixture of hexane and FC-72 (perfluorohexane). Enantiomeric excesses up to 94 and 88 % ee have been achieved in Et(2)Zn and Ph(2)Zn additions, respectively. For the reactions in the biphasic solven

Abstract N‐Alkynylindoles were divergently cyclized for the synthesis of multifused N‐heterocycles. An ortho ‐aryl palladium species was added to the α position of an ynamine to generate ( Z )‐6‐alkylidene/benzylidene‐6 H ‐isoindolo[2,1‐ a ]indoles, while Pt‐catalyzed β‐addition through π‐activation gave 5‐alkyl/arylindolo[2,1‐ a ]isoquinolines. Double cyclizations using PdCl 2 and oxidant afforded bright yellow benzo[7,8]indolizino[2,3,4,5‐ ija ]quinolines, the synthesis of which was also demon

A general method to synthesize halide and halide-free ionic liquids was developed. Direct alkylation of imidazole and pyridine derivatives was performed in the presence of an acid using an orthoester as the alkyl donor yielding ionic liquid products. Residual Cl and water contents of the ionic liquids were determined by ion chromatography and a Karl-Fisher test.

Reported is the utilization of electronically biased conjugated alkynes in the development of highly diastereo- and regioselective dearomative [2 + 2] cycloadditions, alkenylations, and ring expansions of electron-rich indoles. Regioselective protonations of cross- and linear-conjugated alkynes were found to be crucial for accessing various cyclobutene-fused indoline and alkenylated indole derivatives. Furthermore, the facile ring expansion of [2 + 2] keto adducts, which were successfully synthe

Eine kupferkatalysierte asymmetrische allylische Boronierung (AAB) ermöglicht den Zugang zu syn- und anti-1,2-Diolen. Die Methode erleichtert eine iterative Strategie zur Synthese von Polyolen (siehe Schema), wie z. B. vollständig differenziertes L-ribo-Tetrol und geschütztes D-arabino-Tetrol. P=Schutzgruppe.

Electrochemical access to organometallic redox reagents can broaden the potential and impact of organic syntheses, as a selective reaction pathway could be achieved. Herein, we present a unified electrochemical synthetic strategy for the paired electrochemical [2 + 2 + 2] cyclotrimerizations of terminal alkynes to selectively access both 1,3,5- and 1,2,4-regioisomeric trisubstituted benzene derivatives. The regiocontrol in our process can be simply switched by the addition of a carboxylic acid.

The selective electrochemical synthesis of 1H-indazoles and their N-oxides and the subsequent C-H functionalization of the 1H-indazole N-oxides are described. The electrochemical outcomes were determined by the nature of the cathode material. When a reticulated vitreous carbon cathode was used, a wide range of 1H-indazole N-oxides were selectively synthesized, and the electrosynthesis products were deoxygenated to N-heteroaromatics, owing to cathodic cleavage of the N-O bond via paired electroly