Porous size monodisperse methacrylate beads containing amino and hydroxyl groups, which can be used as a platform for the production of chiral separation media, have been prepared using the staged templated suspension polymerization process. The monomers 2-hydroxyethyl methacrylate and several tert-butoxycarbonyl-protected aminoalkyl methacrylates were used for the preparation of both hydroxyl- and amino-functionalized beads. Attachment of a chiral selector based on L-valine-3,5-dimethylanilide through a carbamate and a urea linkage, respectively, provides chiral stationary phases with excellent enantioselectivities in the separation of the enantiomers of 3,5-dinitrobenzamido derivatives of alpha-amino acids. For comparison purposes, a separation medium was also prepared by the direct polymerization of a chiral monomer analogous to the hydroxyethyl methacrylate-based stationary phase. The chiral stationary phases prepared with the N-methyl-2-aminoethyl methacrylate platform exhibit the best selectivity, and separation factors as high as 15 were achieved under normal-phase HPLC conditions.

Dedicated to Professor Oskar Jeger on the occasion of his 80th birthday (27. V. 97) Chiral triols (which may be considered as derivatives of tris(hydroxyinethyl)methane), without (3-5) and with aliphatic (6) or aromatic (7) elongating units, and the 1st-and 2nd-generation benzylic branched bromides, 17, 18,23,24,29, and 30 are subjected to Williamson etherification conditions (NaH in THF). This gave the first 'fully chirdl' dendrimers, with triple branching and with a stereogenic center at each and every branching point (including the central building block; see 33-42, 44, and 46-49). Higher than 2nd-generation dendrimers of this type could not be prepared. Certain combinations of diastereoisomeric 2nd-generation branched bromides, 23,24, 29, and 30, and enantiomeric center-piece triols, 3 and 4, would smoothly react to give the desired dendrimers (e.g., 44, and 46-49) and others would not, with the reactions stopping at the dendritic alcohols containing only two branches (e.g., 45, and 50-53; see Schemes4 and 5). Considering the distance at which the intermediate diastereoisomeric 'doubly coupled' dendritic alcohols differ in their configuration, this diastereodifferentiation or molecular recognition phenomenon (discovered by trying to prepare only 8 out of 23' possible diastereoisomers!) is a most surprising result. All compounds were fully characterized, and the 2nd-generation dendrimers, e.g., 38, 40, and 47 with and without elongation were shown to be monodisperse and without defects, by MALDI-TOF mass spectroscopy (cf. Fig. 4). A simple, unambiguous nomenclature for identification of the novel dendritic compounds is proposed and applied in the Exper. Part.

A parallel library of 108 4-aryl-1,4-dihydropyrimidine (DHPM) enantiomers, which are potential selectors for chiral HPLC separations, was synthesized using the single-step Biginelli multicomponent condensation. The individual compounds were screened by observing the enantioselectivity for resolution on a "brush-type" L-(3,5-dinitrobenzoyl)leucine-based chiral stationary phase, and separation factors alpha up to 12 were achieved. The best candidates from the library contained an ortho-substituted aromatic group at C4 carbon atom of the pyrimidine ring and an alkyl substituent at N1 nitrogen atom. Resolution of the enantiomers of the lead compound, 4-(9-phenanthryl)-DHPM 8, using semipreparative chiral HPLC followed by attachment to monodisperse macroporous aminomethacrylate beads, provided the novel polymer based chiral stationary phase with good enantioselectivities in the resolution of several pi-acidic aryl-dihydropyrimidines and derivatized profens. In addition, 3,5-dinitrobenzamido derivatives of alpha-amino acids could be resolved under normal phase HPLC conditions with separation factors up to 8.

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A straightforward high-yield synthesis for the photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphane oxide (16, IRGACURE 819) involves: i) the reaction of phenyldichlorophosphane, PhPCl2, with sodium to give [Na2(P2Ph2)(tmeda)]6 (5); ii) protonation of 5 with tert-butanol to give 1,2-diphenyldiphosphane, PhHP-PHPh (12); iii) reduction of 12 by sodium to yield [Na(PHPh)]x (13); iv) protonation of 13 with tert-butanol to give phenylphosphane PhPH2 (14) in excellent yields; v) reaction of 14 with 2,4,6-trimethylbenzoylchloride (MesCOCl) in presence of the NaOt-Bu formed in steps ii and iv to give bis(2,4,6-trimethylbenzoyl)phenylphosphane 7; vi) oxygenation of 7 with 30% aqueous hydrogen peroxide to give the final product 16. This reaction can be performed in toluene with about 4 vol-% of tmeda as an activator in a one-pot synthesis without changing the solvent. The structures determined by X-ray diffraction of the unique hexameric aggregate 5 and 16 are reported.