Marine biofouling on artificial surfaces such as ship hulls or fish farming nets causes enormous economic damage. The time for the developmental process of antifouling coatings can be shortened by reliable laboratory assays. For designing such test systems, it is important that toxic effects can be excluded, that multiple parameters can be addressed simultaneously and that mechanistic aspects can be included.
View Article and Find Full Text PDFIsophorone diamine [IPDA, 3-(aminomethyl)-3,5,5-trimethylcyclohexylamine] is a chiral non-C2-symmetric 1,4-diamine which is produced industrially on large scale as the mixture of all four stereoisomers (cis/trans ca. 3:1). Starting from this industrial bulk product, the preparation of the bis-tosyl, bis-Fmoc, bis-Boc and bis-Z derivatives of cis-IPDA, the preparation of the pure cis enantiomers by HPLC on chiral stationary phase, and the assignment of absolute configurations to the isolated enantiomers are described.
View Article and Find Full Text PDFThis article describes the synthesis of a library of structurally diverse bifunctional organocatalysts bearing both a quasi-Lewis acidic (thio)urea moiety and a Brønsted basic tertiary amine group. Sequential modification of the modular catalyst structure and subsequent screening of the compounds in the alcoholytic dynamic kinetic resolution (DKR) of azlactones revealed valuable structure-activity relationships. In particular, a "hit-structure" was identified which provides e.
View Article and Find Full Text PDFNew and improved bis(thio)urea catalysts were synthesized from isophoronediamine (IPDA) and tested in the Morita-Baylis-Hillman reaction. The best results were achieved in the reaction of 2-cyclohexen-1-one with cyclohexanecarbaldehyde, using the catalyst depicted above, in combination with a novel base (N,N,N',N'-tetramethylisophoronediamine, TMIPDA) in toluene. The desired Morita-Baylis-Hillman product was obtained in 75% yield and 96% ee.
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