Diastereoselective Ugi reactions of DMAP-based aldehydes with α-amino acids and tert-butyl isocyanide were examined. The reactions of 4-(dimethylamino)-2-pyridine-carboxaldehyde with various α-amino acids afforded 2-substituted DMAP derivatives with low diastereoselectivity. On the contrary, reactions with 4-(dimethylamino)-3-pyridine-carboxaldehyde delivered 3-substituted DMAP derivatives with moderate to high diastereoselectivity. The combination of α-amino acid and DMAP-based aldehyde is thus important to achieve high diastereoselectivity. Kinetic resolution of a secondary alcohol using a chiral DMAP derivative obtained through these reactions was also examined.

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Twenty-four D-A'-π-A dyes were rapidly synthesized through a one-pot three-component Suzuki-Miyaura coupling reaction, which was assisted by microwave irradiation. We measured the absorption spectra, electrochemical properties, and solar-cell performance of all the synthesized dyes. The D5 πA4 dye contained our originally designed rigid and nonplanar donor and exerted the highest efficiency at 5.4 %. The short-circuit current (Jsc ) was the most important parameter for the conversion efficiency (η) in the case of the organic D-A'-π-A dyes. Optimal ranges for the D-A'-π-A dyes were observed for high values of Jsc /λmax at λ=560-620 nm, an optical-absorption edge of λ=690-790 nm, and EHOMO and ELUMO values of <1.14 and -0.56 to -0.76 V, respectively.