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Dedicated to Prof. Dieter Seebach on the occasion of his 65th birthday During studies of aziridination of a,b-unsaturated amides with diaziridine, we found that we could prepare both the cis-and trans-aziridinecarboxamides by choosing an appropriately substituted diaziridine. While 3-monosubstituted diaziridine 2 was suitable for the trans-selective aziridination, employment of 3,3-dialkyldiaziridine 1 resulted in the formation of cis-aziridine carboxamides, irrespective of the geometry of the substrate (Scheme 1 and Tables 1 and 2). To elucidate the unique nonstereospecificity and to expand these aziridinations to asymmetric ones, several optically active diaziridines were newly prepared. Aziridination with an optically active 3-monosubstituted diaziridine, 3-cyclohexyl-1-[(1R)-1-phenylethyl]diaziridine 16, proceeded smoothly with high trans-selectivity as well as excellent enantioselectivity (up to 98% ee; see Table 3). On the other hand, highly enantioselective cis-aziridination was achieved (> 99% ee) with optically active 3,3-dimethyl-1-[(1R)-1-phenylethyl]diaziridine 15, though the yield was low (4%). This aziridination was considered to proceed stepwise by way of the enolate intermediate (Scheme 2). Careful inspection of the stereochemistry and its solvent-dependence suggested that the diastereoselection of the reaction was kinetically controlled: the 1,4-addition of N-lithiated diaziridine was a crucial step for determination of the stereochemical course of the aziridination (Figs. 2 ± 4).

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Microwave excited plasma source with slot antenna in water is a novel plasma applicable to materials processing in liquid. In order to apply this microwave plasma source to a practical use for solute decomposition, it is necessary to evaluate the decomposition efficiency for refractory organic solutes and understand the decomposition process of solution as well. In this paper, the microwave plasma treatment was demonstrated through decomposition of refractory organic solutes such as acetic acid, polyvinyl alcohol (PVA), and 4-chloro-2-methylphenoxy acetic acid (MCPA) in aqueous solutions. Total organic carbon concentration and high-performance liquid chromatography measurements revealed that the refractory organic substances such as acetic acid, PVA, and MCPA were decomposed by microwave plasma. Intermediate products of MCPA were investigated by gas chromatography coupled to a mass spectrometry and ion chromatograph during MCPA degradation using microwave excited plasma.

Active 2-Acyl Aziridines. -Conjugate addition of O-alkylhydroxylamines (II) and (VI) to α,β-unsaturated ketones (I) and (V) in the presence of a chiral scandium-BINOL-derived phosphate complex represents a novel efficient approach to the synthesis of enantiopure β-alkoxamino ketones (III) and (VII), respectively. Base-mediated elimination then proceeds without racemization and in almost quantitative yields to furnish optically active 2-acylaziridines [cf. (IV)]. A remarkably high asymmetric amplification is observed in the conjugate addition reaction. Additionally, it is shown that the elimination reaction of racemic β-methoxamino ketone (III) in the presence of La-chiral BINOL complex proceeds with kinetic resolution. -(JIN, X. L.; SUGIHARA, H.; DAIKAI, K.; TATEISHI, H.; JIN, Y. Z.; FURUNO, H.; INANAGA*, J.; Tetrahedron 58 (2002) 41, 8321-8329; Inst. Fundam. Res. Org. Chem., Kyushu Univ., Hakozaki, Fukuoka 812, Japan; Eng.) -Mischke 10-105 2002 Aziridine derivatives