摘要:
A process for the hydrogenation of imines with hydrogen under elevated pressure in the presence of iridium catalysts and with or without an inert solvent, wherein the reaction mixture contains an ammonium or metal chloride, bromide or iodide and additionally an acid.
摘要:
A process for the hydrogenation of imines with hydrogen under elevated pressure in the presence of iridium catalysts and with or without an inert solvent, wherein the reaction mixture contains hydrogen iodide.
摘要:
The asymmetric hydrogenation of aliphatic .alpha.-keto esters in the presence of rhodium catalysts which contain as chiral ligand a diphosphine of formula IV(R.sub.3).sub.2 P--Q--P(R.sub.3)hd 2 (IV)wherein R.sub.3 is phenyl, C.sub.1 -C.sub.6 alkylphenyl or C.sub.1 -C.sub.6 alkoxyphenyl, and Q is [2,2,1]-bicyloheptan-1,2-ylene or [2,2,1]-bicyclohept-4,5-en-1,2-ylene, gives the corresponding (R)- or(S)-.alpha.-hydroxycarboxylic acid esters in high rates of chemical conversion and in high enantiomer excesses.
摘要:
Compounds of general formula I or Ia ##STR1## or mixtures thereof, wherein the groups P-L-P are a ligand from the group comprising diphosphine and diphosphinite, in which the secondary phosphine groups or phosphinite groups P are coupled via 2 to 4 C atoms, and which form a 5-, 6- or 7-membered ring with the Ir atoms, X, X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5 and X.sup.6 independently of the others are Cl, Br or I, or X.sup.1 and X.sup.6 and H and X.sup.2, X.sup.3, X.sup.4 and X.sup.5 independently of the others are Cl, Br or I, or X.sup.1 and X.sup.5 and H and X.sup.2, X.sup.3, X.sup.4 and X.sup.6 independently of the others are Cl, Br or I, and M.sup..sym. is an alkali metal cation or quaternary ammonium. The compounds are suitable as homogeneous catalysts for the (preferably) asymmetric hydrogenation of N-substituted imines to secondary amines.
摘要:
Compounds of the formulae I and Ia in the form of mixtures of diastereomers or pure diastereomers, (I), (Ia), where R1 is a hydrogen atom or C1-C4-alkyl and R′1 is C1-C4-alkyl; X1 and X2 are each, independently of one another, a sec-phosphino group; T is C6-C20-arylene or C4-C18-heteroarylene having heteroatoms selected from the group consisting of O, S, —N═ and N(C1-C4-alkyl); v is 0 or an integer from 1 to 4; X1 is bound in the ortho position relative to the T-C* bond; Q is vinyl, methyl, ethyl, —CH2—OR, —CH2—N(C1-C4-alkyl)2 or a C- or S-bonded chiral group which directs metals of metallation reagents into the ortho position; R is hydrogen, a silyl radical or an aliphatic, cycloaliphatic, aromatic or aromatic-aliphatic hydrocarbon radical which has from 1 to 18 carbon atoms and is unsubstituted or substituted by C1-C4-alkyl, C1-C4-alkoxy, F or CF3; are ligands for metal complexes as homogeneous catalyst in asymmetric syntheses.
摘要:
Compounds of the formula (I) in the form of racemates, mixtures of stereoisomers or optically pure stereoisomers, formula (I), where X1 and X2 are each, independently of one another, a secondary phosphino group; R1 is a halogen atom or a—substituent bound via a C atom, N atom, S atom, Si atom, a P(O) group or a P(S) group to the cyclopentadienyl ring; R2 is C1-C4-alkyl or phenyl; m is from 1 to 3 and n is 0 or from 1 to 5, are ligands for complexes of transition metals as enantioselective and homogeneous catalysts. As a result of the substitution, the conversion, the stereoselectivity and/or the configuration of the adduct formed can be influenced and optimization of catalysts can be made possible in this way.
摘要:
Compounds of formula (I), wherein R1 and R2 are, independently of one another, H,C1-C6alkyl, C1-C6halogenalkyl, C1-C6alkoxyl, C1-C6alkoxy-C1-C6alkyl, or C1-C6alkoxy-C1-C6alkyloxy, and R3 is C1-C6alkyl, are obtainable in high yiedls by stereoselective addition of R3-substituted propionic acid esters to R1- and R2-substituted benzaldehydes of formula R—CHO to form corresponding 3-R-3-hydroxy-2-R3-propionic acid esters, conversion of the OH group to a leaving group, subsequent regioselective elimination to form 3-R-2-R3-propenic acid esters, and reduction to corresponding 3-R-2-R3-allyl alcohols and their enantioselective hydrogenation, wherein R is (a).
摘要:
Reaction products of an iridium(III) salt or a hydrate thereof, a diphosphine having secondary phosphine groups and a metal or ammonium chloride, bromide or iodide are excellent hydrogenation catalysts for ketimine. Using chiral diphosphines and prochiral ketimines, diastereoisomeric secondary amines are obtained in high optical yields.
摘要:
Compounds of formula I ##STR1## wherein R.sub.1 is C.sub.1 -C.sub.8 alkyl, phenyl or phenyl which is substituted by 1 to 3 C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy groups; R.sub.2 is a radical of formula II ##STR2## wherein R.sub.12 is C.sub.1 -C.sub.5 alkyl which is partially or completely fluorinated;R.sub.13 is C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --SiR.sub.4 R.sub.5 R.sub.6, halogen, --SO.sub.3 M, CO.sub.2 M, --PO.sub.3 M, --NR.sub.7 R.sub.8 or --[.sup..sym. NR.sub.7 R.sub.8 R.sub.9 ]X.sup..crclbar. ;m is an integer from 1 to 3, n is 0 or an integer from 1 to 4, and the sum of m+n is 1 to 5;R.sub.3, R.sub.10, R.sub.11 have each independently of one another the same meaning as R.sub.2 or are each independently of one another C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, phenyl, C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl, or phenyl which is substituted by one to three identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, --SiR.sub.4 R.sub.5 R.sub.6, halogen, --SO.sub.3 M, --CO.sub.2 M, --PO.sub.3 M, --NR.sub.7 R.sub.8 and --[.sup..sym. NR.sub.7 R.sub.8 R.sub.9 ]X.sup..crclbar. ;R.sub.4, R.sub.5 and R.sub.6 are each independently of one another C.sub.1 -C.sub.12 alkyl or phenyl;R.sub.7 and R.sub.8 are H, C.sub.1 -C.sub.12 alkyl or phenyl orR.sub.7 and R.sub.8, taken together, are tetramethylene, pentamethylene or 3-oxa-1,5-pentylene;R.sub.9 is H or C.sub.1 -C.sub.4 alkyl,M is H or an alkali metal, X.sup..crclbar. is the anion of a monobasic acid, and * is a stereogenic carbon atom, in the form of their racemates and diastereoisomers or mixtures of diastereoisomers. Rhodium and iridium complexes with these ligands are suitable for use as homogeneous enantioselective catalysts for the hydrogenation of prochiral compounds containing carbon double bonds or carbon/hetero atom double bonds.
摘要:
Compounds of the formula I ##STR1## wherein R.sub.1 is C.sub.1 -C.sub.8 alkyl, phenyl or phenyl which is substituted by 1 to 3 C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy groups; R.sub.2 and R.sub.3 are each independently of the other typically C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, phenyl, or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl, or phenyl which is substituted by one to three identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen; R.sub.10 and R.sub.11 are identical and are typically C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl or phenyl which is substituted by 1 to 3 identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen; or R.sub.10 and R.sub.11 are different and are C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.12 cycloalkyl, C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.5 -C.sub.12 cycloalkyl, phenyl or phenyl which is substituted by 1 to 3 identical or different members selected from the group consisting of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen, and * denotes a stereogenic carbon atom, in the form of their racemates and diastereoisomers or mixtures of diastereoisomers.Rhodium and iridium complexes with these ligands are suitable for use as homogeneous enantioselective catalysts for the hydrogenation of prochiral compounds containing carbon double bonds or carbon/hetero atom double bonds.