Shuichi Oi

Rhodium-catalyzed conjugate addition of aryl- and alkenyl-stannanes to α,β-unsaturated carbonyl compounds

Abstract The addition of aryl- or alkenyl-trimethylstannanes to α,β-unsaturated carbonyl compounds in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN) 2 ]BF 4 ) and water to afford the conjugate addition products in good yields was examined. It was observed that addition of water was necessary for the reaction to proceed smoothly. The aryl- or alkenyl-rhodium complex, which is generated by the transmetalation from the organotin compound, is considered to be the active catalytic species.

Regioselective hydroesterification of styrene catalyzed by cationic palladium(II) complexes under mild conditions

Abstract The cationic palladium(II) complex [Pd(MeCN)2(PPh3)2](BF4)2 was found to be an active catalyst for hydroesterification of styrene using CO and methanol under very mild conditions. The system, Pd(OAc)2-PPh3-p-toluenesulfonic acid, which should give rise to a cationic species in situ, was also effective to produce the branched ester regioselectively in an excellent yield at ambient temperature. Asymmetric hydroesterification of styrene by the use of chiral phosphines as ligands was also studied.

Pd-Catalyzed β-Selective Direct C–H Bond Arylation of Thiophenes with Aryltrimethylsilanes

Direct arylation of thiophenes and benzothiophenes with aryltrimethylsilanes was effectively catalyzed by PdCl(2)(MeCN)(2) in the presence of CuCl(2) as an oxidant. The reaction preferentially occurred at the β-position of both thiophenes and benzothiophenes.

Nitrogen-directed ortho-selective homocoupling of aromatic compounds catalyzed by ruthenium complexes.

A nitrogen-directed regioselective homocoupling reaction of aromatic compounds has been found to be catalyzed by a ruthenium complex in the presence of methallyl acetate as a hydrogen scavenger.

Light blue and green thermally activated delayed fluorescence from 10H-phenoxaborin-derivatives and their application to organic light-emitting diodes

New luminescent compounds consisting of 10H-phenoxaboryl groups as electron-accepting units and carbazole (9), 9,9-dimethylacridane (10), or phenoxazine (11) as an electron-donating unit have been synthesized. Compounds 10 and 11 showed thermally activated delayed fluorescence (TADF) with light blue and green emissions, respectively, with very high PL quantum yields (PLQYs), however, compound 9 exhibited only a prompt emission and no delayed component. Photoluminescence studies and quantum chemical calculation based on density functional theory (DFT) and time-dependent density functional theory (TD-DFT) revealed that in comparison with compound 9, the HOMO and LUMO for compounds 10 and 11 are well separated, resulting in lowering of ΔEST and effective reverse intersystem crossing (RISC) between a lowest triplet excited state (T1) and a lowest singlet excited state (S1). Organic light-emitting diodes (OLEDs) using compounds 10 and 11 exhibited light blue and green emissions with very good maximum ηext of 15.1% and 22.1%, respectively.

Cationic palladium(II) complex-catalyzed hetero Diels-Alder reaction of dienes with aldehydes

Cationic palladium(II) complexes, [PdL2(RCN)2](BF4)2, have been found to catalyze the hetero Diels-Alder reaction of nonactivated simple dienes with aldehydes, affording the corresponding 5,6-dihydro-2H-pyrans in good yields under mild conditions.

Rhodium-catalyzed addition of arylstannanes to carbon–heteroatom double bond

Abstract The addition of arylstannanes to the carbon–heteroatom double bond in the presence of a catalytic amount of a cationic rhodium complex ([Rh(cod)(MeCN) 2 ]BF 4 ) was examined. The reactions of aldehydes, α-dicarbonyl compounds, and N -substituted aldimines with the arylstannanes gave corresponding alcohols, α-hydroxy carbonyl compounds, and amines, respectively. An arylrhodium complex generated by the transmetalation with the arylstannane was probably the active catalytic species.

A cationic palladium(II) complex-catalyzed Diels-Alder reaction

Abstract A cationic palladium(II) complex, [PdL 2 (RCN) 2 ](BF 4 ) 2 , has been found to catalyze the Diels-Alder reaction of α,β-unsaturated carbonyl compounds with dienes, affording the corresponding cycloadducts in good yields. Excellent enantioselectivity can be achieved in the reaction of N -acryloyloxazlidinone and cyclopentadiene by use of a chiral ligand, BINAP.

Rhodium-catalyzed arylation and alkenylation of imines with organostannanes

Abstract A rhodium complex catalyzed the addition of aryl- and alkenyl-stannanes to activated aldimines under mild and neutral conditions, affording the corresponding amines in good yields.

Rh-catalyzed reductive coupling reaction of aldehydes with conjugated dienes promoted by triethylborane.

Rh(I) catalyzes the reductive coupling reaction of a wide variety of aldehydes with conjugated dienes in the presence of a stoichiometric amount of triethylborane to provide homoallyl alcohols in a single operation.