Seijiro Matsubara

Palladium catalyzed reaction of 2-alkynylanilines with allyl chlorides. Formation of 3-allylindoles

Abstract Pd(II) catalyzed reaction of N-carbomethoxy-2-alkynylanilines with allyl chlorides produces 2-alkyl-3-allyl-N-carbomethoxyindoles in the presence of oxirances; Aminopalladation of a N-carbomethoxy-2-alkynylaniline gives 3-(N-carbomethoxyindolyl)palladium intermediate, which regioselectively attacks on the γ position of chlorides to give 3-allyl-2-alkylindoles with concurrent regeneration of Pd(II) catalyst.

Nickel-Catalyzed Decarbonylative Addition of Phthalimides to Alkynes

An intermolecular nickel-catalyzed addition reaction has been developed where N-arylphthalimides react with alkynes to afford substituted isoquinolones. A mechanistic rationale is proposed, implying nucleophilic attack of Ni(0) to an amide as the primary step of the catalytic cycle.

Asymmetric Catalytic Cycloetherification Mediated by Bifunctional Organocatalysts

Oxacyclic structures such as tetrahydrofuran (THF) rings are commonly found in many bioactive compounds, and this has led to several efforts toward their stereoselective syntheses. However, the process of catalytic asymmetric cycloetherification for their straightforward synthesis has remained a challenge. In this study, we demonstrate a novel asymmetric synthesis method for THF via the catalytic cycloetherification of ε-hydroxy-α,β-unsaturated ketones mediated by cinchona-alkaloid-thiourea-based bifunctional organocatalysts. This catalytic process represents a highly practical cycloetherification method that provides excellent enantioselectivities, even with low catalyst loadings at ambient temperature.

Nickel-Catalyzed Decarbonylative Addition of Anhydrides to Alkynes

An intermolecular nickel-catalyzed addition reaction has been developed where phthalic anhydrides react with alkynes to afford substituted isocoumarins. A mechanistic rationale is proposed, implying reductive elimination of Ni(0) promoted by ZnCl(2) cocatalyst as the key step of the catalytic cycle.

Nickel-catalyzed decarboxylative carboamination of alkynes with isatoic anhydrides.

An intermolecular nickel-catalyzed addition reaction in which isatoic anhydrides react with alkynes to afford substituted quinolones has been developed. A mechanistic rationale is proposed, implying oxidative addition of Ni(0) to a carbamate, which allows intermolecular addition to alkynes via decarboxylation.

Regioselective stannylmetalation of acetylenes in the presence of transition-metal catalyst

Abstract The reaction of terminal acetylenes with Bu 3 SnMgMe, Bu 3 SnA1Et 2 , or (Bu 3 Sn) 2 Zn in the presence of various transition-metal catalysts provides vinylstannanes in good yields. Whereas copper catalysed stannylmagnesation of 4-benzyloxy-1-butyne gives (E)-4-benzyloxy-1-tributylstannyl-1-butene exclusively, palladium catalysed stannylzincation affords 4-benzyloxy-2-tributylstannyl-1-butene preferentially.

Transition-metal catalyzed oxidation of alcohols to aldehydes and ketones by means of Me3SiOOSiMe3

Pyridinium dichromate-Me3SiOOSiMe3 system has been found to be effective for the oxidation of alcohols to the corresponding carbonyl compounds. Selective oxidation of primary alcohols in the presence of secondary ones with RuCl2(PPh3)3-Me3SiOOSiMe3 is also described.

Nickel-Catalyzed Cycloaddition of o-Arylcarboxybenzonitriles and Alkynes via Cleavage of Two Carbon–Carbon σ Bonds

An intermolecular cycloaddition reaction has been developed, where o-arylcarboxybenzonitriles react with alkynes to afford coumarins in the presence of Ni(0)/P(CH(2)Ph)(3)/MAD as a catalyst. The reaction process displays an unusual mechanistic feature-the cleavage of two independent C-CN and C-CO bonds.

Yb(CN)3-catalyzed reaction of aziridines with cyanotrimethylsilane. A facile synthesis of optically pure β-amino nitriles

Abstract Reaction of a N-tosylaziridine with cyanotrimethylsilane under lanthanoid tricyanide catalysis gives a N-tosyl β-amino nitrile by selective attack of cyanide at less substituted carbon of the ring; optically pure 2-substituted aziridine affords the corresponding amino nitrile with perfect retention of the stereochemistry of stereogenic center.

Regio- and stereo-selective synthesis of vinylstannanes. Transition-metal catalyzed stannylmetalation of acetylenes and conversion of enol triflates and vinyl iodides into vinylstannanes

Abstract Two new methods for the regio- and stereo-selective synthesis of vinylstannanes are described. (i) The reaction of terminal acetylenes with n-Bu 3 SnMgMe, n-Bu 3 SnAlEt 2 , or (n-Bu 3 Sn) 2 Zn in the presence of various transition-metal catalysts provides vinylstannanes in good yields. Whereas copper-catalyzed stannylmagnesation of 4-benzyloxy-1-butyne gives ( E )-4-benzyloxy-1-tributylstannyl-1-butene exclusively, palladium-catalyzed stannylzincation affords 4-benzyloxy-2-tributylstannyl-1-butene preferentially. (ii) Treatment of enol triflates or vinyl iodide with Me 3 Sn-MgMe in the presence of CuCN catalyst gives vinylstannanes in good yields.