Hoffmann-la Roche Inc.

Marco Cereghetti

Arthur Boller

Emil A Broger

Hanspeter Scherrer

Alain Rageot

Frank Kienzle

Rudolf Schmid

Joseph Foricher

Bernd Heiser

Novel, chiral diarsine compounds, which are present in the (R)- or (S)- or (rac)-form, of the formula ##STR1## wherein R signifies an optionally substituted aryl from the group of phenyI, naphthyl, furyl and thienyl; C.sub.3-8 -cycloalkyl or C.sub.1-8 -alkyl;

Chiral diarsine compounds

The present invention is concerned with novel optically active phosphorus compounds of the general formula ##STR1## wherein R and R.sup.1 each independently signify hydroxy, a protected hydroxy group, lower alkyl or lower alkoxy and

Optically active phosphorous compounds

Phosphorus compounds

Novel chiral phosphorus compounds of the formula ##STR1## wherein R signifies lower alkyl, R.sup.1 signifies phenyl and R.sup.2 and R.sup.3 signify hydrogen or lower alkoxy, which are suitable in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and for enantioselective hydrogen displacements in prochiral allylic systems.

Chiral phosphorus compounds

A process for the resolution of racemic diphosphine oxides into the optically active antipodes by reacting the racemate with a resolving agent comprising using a carbamate or thiocarbamate of an optically active .alpha.-hydroxycarboxylic acid or .alpha.-aminocarboxylic acid as the resolving agent.

Process for the resolution of racemic diphosphine oxides

Optically active pyrimidines of the formula ##STR1## wherein Z is --(CH.sub.2).sub.n -- or --(CH.sub.2).sub.n --O-- wherein n is an integer of 1 to 4 and each of the symbols X is a nitrogen atom and each of the symbols Y is --CH-- or each of the symbols Y is a nitrogen atom and each of the symbols X is --CH--, useful for electro-optical purposes, as well as liquid crystalline mixtures for electro-optical purposes containing compounds of the formula Ia and/or Ib, are described. The compounds of formulas Ia and Ib are useful for electro-optical purposes, for example, in electro-optical apparatuses.

Pyrimidine derivatives

Phenyl-pyrimidines of the formula ##STR1## wherein R.sub.1 and R.sub.2 are as hereinafter set forth, are described. The end products are useful as liquid crystals.

Phenyl-pyrimidines

Compounds of the formula ##STR1## wherein when X is nitrogen, Y and Z are --CH--; or when Y is nitrogen, X and Z are --CH--; or when Z is nitrogen, X and Y are --CH--; and one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 1 to 7 carbon atoms, straight-chain alkoxy of 1 to 7 carbon atoms or straight-chain alkanoyloxy of 2 to 7 carbon atoms, Prepared by a variety of methods, are described. The compounds of the invention are useful as components of nematic mixtures.

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Basel, Switzerland

Marco Cereghetti