P-Chiral 1,7-diphosphanorbornenes: from asymmetric phospha-Diels-Alder reactions towards applications in asymmetric catalysis.

A straightforward synthesis of P-chiral polycyclic phosphines by an asymmetric Diels-Alder reaction of 1-alkyl-1,2-diphospholes and (5R)-(l-menthyloxy)-2(5H)-furanone (MOxF) is presented. The [4 + 2] cycloaddition reaction of 1,2-diphospholes 1-3 with MOxF (4) proceeded with high diastereoselectivity (de up to 90%) resulting in the corresponding enantiopure anti-endo-1,7-diphosphanorbornenes 5a-7a. The absolute configuration of 5-7 was proved by a variety of 1D/2D NMR correlation methods.

Covalent self-assembly of the specific RSSR isomer of 14-membered tetrakisphosphine.

The first representative of the specific RSSR isomer of 14-membered tetrakisphosphine has been obtained instead of the RRRR/SSSS isomer predicted according to the empirical rule formulated recently. The geometry of the obtained 14-PN is preorganized for the dicopper complex formation with the unique coordination mode in the row of PN corands.

Amphiphilic macrocycles bearing biofragment: molecular design as factor controlling self-assembly.

Two novel macrocyclic 6-methyluracilic amphiphiles (uracilophanes) with four (UP1) and two (UP2) uracil moieties and ammonium groups have been synthesized. Tetracationic multi-uracilophane is composed of two macrocyclic units bridged each other with an external methylene spacer, while in the cryptand-like dicationic uracilophane pyrimidinic moieties are connected with an internal methylene spacer. This internal spacer provided a conformational rigidity to the macrocycle.

[Geometrical configuration of 12,13-epoxy-9,11-octadecadienoic acid, a product of the reaction catalyzed by flaxseed allene oxide synthase (CYP74A)].

The geometrical configuration of a short-living allene oxide reaction product that arises under the catalysis by flaxseed allene oxide synthase (CYP74A) was studied by NMR spectroscopy. The structure of (9Z,11E)-12,13-epoxyoctadeca-9,11-dienoic acid was established for it from the results of the nuclear Overhauser effect. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol.