Long-wavelength visible to near infrared photoluminescence from carbon-bridged styrylstilbene and thiadiazole conjugates in organic and aqueous media.

Donor-acceptor-donor conjugates composed of electron-donating carbon-bridged styrylstilbene (COPV2) and electron-accepting thiadiazole derivatives equipped with carbazolyl (Cz) terminators, Cz-COPV2-A-COPV2-Cz (A = benzothiadiazole (BTz), naphthobis(thiadiazole) (NTz), or benzobis(thiadiazole) (BBTz)), were newly synthesized and found to serve as efficient and stable long-wavelength photoluminescent dyes in organic and aqueous media. In particular, Cz-COPV2-BBTz-COPV2-Cz showed photoluminescence in the near infrared region (895-927 nm) with a photoluminescence quantum yield (PLQY) of up to 0.19 in cyclohexane and of 0.

Asymmetric Michael Reaction of α-CF Thioester and α,β-Unsaturated Aldehyde Catalyzed by Diphenylprolinol Silyl Ether.

Asymmetric Michael reaction of α-CF thioester and α,β-unsaturated aldehyde is catalyzed by diphenylprolinol silyl ether to afford the trifluoromethyl substituted Michael product with excellent enantioselectivity. Although the Michael products were generated as a mixture of syn- and anti-isomers, they can be transformed to single isomers of other useful compounds, such as lactone, lactam, piperidine, dihydropyran containing trifluoromethyl groups, or fluoro substituents.

Re(I)-catalyzed hydropropargylation of enamides: a useful method for the preparation of 4-pentynylamine derivatives.

Hydropropargylation of enamides was achieved in good yields through the 1,4-addition of enamides to the α,β-unsaturated carbene complex intermediate, followed by intramolecular hydrogen transfer to the iminium carbon. This method is useful for the synthesis of 4-pentynylamine derivatives from enamides and easily available propargyl ether. Moreover, tandem cyclization reaction was achieved to afford a pyrrolidine derivative in a single operation by using a secondary enamide.

Re(I)-Catalyzed Hydropropargylation of Silyl Enol Ethers Utilizing Dynamic Interconversion of Vinylidene-Alkenylmetal Intermediates via 1,5-Hydride Transfer.

Re(I)-catalyzed hydropropargylation reaction of silyl enol ethers was realized utilizing dynamic interconversion of vinylidene-alkenylmetal intermediates, where alkenylmetals underwent 1,5-hydride transfer of the α-hydrogen to generate vinylidene intermediates. Furthermore, this process was found to be in an equilibrium.