Asymmetric cycloaddition reactions between several nitrile oxides and 3-(2-alkenoyl)-2-oxazolidinones and 2-(2-alkenoyl)-3-pyrazolidinone derivatives were carried out in the presence of chiral binaphthyldiimine (BINIM)-Ni(II) complexes as catalysts. Using (R)-BINIM-4(3,5-xylyl)-2QN-Ni(II) complex (30 mol %), good regioselectivity (4-Me/5-Me = 85:15) along with high enantioselectivity (96% ee) of the 4-Me adduct were obtained for the reaction between isolable 2,4,6-trimethylbenzonitrile oxide and 3-crotonoyl-5,5-dimethyl-2-oxazolidinone. Substituted and unsubstituted benzonitrile oxides and aliphatic nitrile oxides, which were generated from the corresponding hydroximoyl chloride in the presence of MS 4A, were reacted with 3-crotonoyl-5,5-dimethyl-2-oxazolidinone, 5,5-dimethyl-3-(2-pentenoyl)-2-oxazolidinone, 5,5-dimethy-3-[3-(ethoxycarbonyl)propenoyl]-2-oxazolidinone, 1-benzyl-2-crotonoyl-5,5-dimethyl-3-pyrazolidinone, and 1-benzyl-2-[3-(ethoxycarbonyl)propenoyl]-5,5-dimethy-3-pyrazolidinone in the presence of (R)-BINIM-4Ph-2QN-Ni(II) or (R)-BINIM-4(3,5-xylyl)-2QN-Ni(II) complexes (10-30 mol %) as catalysts to give the corresponding cycloadducts in high yields, with high regioselectively (4-R/5-R = 85:15-99:1) and with moderate to high enantioselectivities (42-95% ee) of the 4-R adducts. Higher enantioselectivities and regioselectivities were obtained for the reactions using pyrazolidinone derivatives as the dipolarophiles. For the cycloadditions of 2-(2-alkenoyl)-1-benzyl-5,5-dimethyl-3-pyrazolidinones catalyzed by (R)-BINIM-4(3,5-xylyl)-2QN-Ni(II) complex (30 mol %), the enantioselectivity varied from 75% to 95% ee. The reactions between several nitrile oxides and 2-acryloyl-1-benzyl-5,5-dimethyl-3-pyrazolidinone in the presence of (R)-BINIM-4(3,5-xylyl)-2QN-Ni(II) complex (10 mol %) resulted in enantioselectivities (79-91% ee) that exceed those of previously reported enantioselective cycloadditions of acrylic acid derivatives. Furthermore, studies using a molecular modeling program using PM3 calculations were carried out to gain insight into the mechanisms of the asymmetric induction.

The first successful example of a catalytic enantioselective intramolecular Tishchenko reaction of a meso-dialdehyde in the presence of a chiral iridium complex is described.

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We previously proposed the circular defect in two-dimensional photonic crystal (CirD) laser based on a GaAs/AlGaAs multilayer wafer, which is fabricated by dry etching. This CirD laser uses InAs quantum dot (QD) layers as the gain medium, but this inhibits vertical dry etching. We improved the dry etching process by introducing three QD layers and threestep dry etching for fabricating the CirD laser. As a result, CirD structures with good etching profiles could be fabricated and excellent optical properties were obtained. We observed lasing by a CirD laser fabricated by deep etching under photoexcitation measurement for the first time.