Preparation of optically active hydrazines and amines
AssigneeE. I. Du Pont de Nemours and Company
InventorMark J. Burk
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Abstract
A process for the asymmetric hydrogenation of N-acylhydrazones to optically active N-acylhydrazines in the presence of a chiral phospholane catalyst complex, a process for the reductive N--N bond cleavage of N-acylhydrazine to amines with samarium diiodide, and a multistep process for converting keto group-bearing compounds to the corresponding optically active amino group-bearing compounds are disclosed.
Claims10
A process for the asymmetric hydrogenation of N-acylhydrazones comprising reacting with hydrogen a compound of formula 2 ##STR24## wherein R.sup.1 and R.sup.2 are not the same and are each C.sub.1 to C.sub.15 cyclic, linear or branched alkyl;
- C.sub.1 to C.sub.15 cyclic, linear or branched alkyl substituted with at least one of hydrogen, halogen, alkyl, perfluoroalkyl, alkoxy, aryl, acyl, aryloxy, nitro, amino, carboalkoxy, trialkylsilyl, triphenylsilyl, vinyl, or alkynyl, C.sub.1 to C.sub.8 fluoroalkyl;
- C.sub.1 to C.sub.8 perfluroalkyl;
- aryl;
- aryl substituted with at least one of hydrogen, halogen, alkyl, perfluoroalkyl, alkoxy, aryl, acyl, aryloxy, nitro, amino, carboalkoxy, trialkylsilyl, triphenylsilyl, vinyl, or alkynyl;
- aralkyl;
- ring substituted aralkyl substituted with at least one of hydrogen, halogen, alkyl, perfluoroalkyl, alkoxy, aryl, acyl, aryloxy, nitro, amino, carboalkoxy, trialkylsilyl, triphenylsilyl, vinyl, or alkynyl;
- carboalkoxy, carboamido, acyl, vinyl, substituted vinyl, alkynyl and
- R.sup.3 is aryl, aryl substituted with at least one of hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, nitro or amino, or a linear, branched or cyclic C.sub.1 to C.sub.8 alkyl;
- in the presence of a catalyst comprising a complex wherein a transition metal is bonded to both phosphorus atoms of a chiral ligand selected from the group consisting of:
- (S)-(-)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl;
- (R)-(+)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl;
- (2S,4S)-2,4-bis(diphenylphosphino)pentane;
- (2R,4R)-2,4-bis(diphenylphosphino)pentane;
- (2S,3S)-bis(diphenylphosphino)butane;
- (2R,3R)-bis(diphenylphosphino)butane;
- (+)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane;
- (-)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane;
- phenyl-4,6-O-(R)-benzylidene-2,3-O-bis(diphenylphosphino)-.beta.-D-glucopyr anoside;
- phenyl-4,6-O-(S)-benzylidene-2,3-O-bis(diphenylphosphino)-.beta.-D-glucopyr anoside;
- a chiral ligand of formula I and II ##STR25## wherein n is an integer from 1 to 12;
- Y is each independently hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, nitro, dialkylamino, vinyl, substituted vinyl, alkynyl, of sulfonic acid;
- m is an integer from 1 to 4;
- R is a radical comprising linear, branched or cyclic C.sub.1 to C.sub.8 alkyl;
- linear, branched or cyclic C.sub.1 to C.sub.8 fluoroalkyl;
- linear, branched or cyclic C.sub.1 to C.sub.8 perfluroalkyl;
- aryl;
- aryl substituted with at least one of hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, nitro, amino, vinyl, alkynyl, or sulfonic acid;
- aralkyl;
- ring-substituted aralkyl substituted with at least one of hydrogen, halogen, alkyl, alkoxy, aryl, aryloxy, nitro, amino, vinyl, alkynyl, or sulfonic acid;
- provided that the catalyst is other than ruthenium (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl) dichloride dimer or bis-2-(methylallyl)ruthenium ((2S,5S)-2,5-dimethylphospholano)benzene;
- to yield an optically active mixture of enantomeric N-acylhydrazines of formula (3A) and (3B) ##STR26## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above.
Dependencies are inferred from the claim text.