Chiral phosphanes for use in asymmetric syntheses

1. A compound of the formula (I),

wherein:

B is a C 1 -C 4 -alkylene radical which may be singly or multiply substituted by C 1 -C 4 -alkyl;

R 2 is alkyl;

R 3 is alkyl;

G is chlorine or hydrogen; and

R′ and R″ are each, independently of one another, aryl or alkyl.

2. A compound according to claim 1 , selected from the following:

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis-[(diphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(ethoxycarbonylmethoxy)-6-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(diphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)-biphenyl-2,2′-diyl]bis[(dicyclohexyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(ethoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(dicyclohexyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(di-3,5-di-tert-butyl-4-methoxyphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(ethoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]-bis[(di-3,5-di-tert-butyl-4-methoxyphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(di-3,5-dimethyl-4-methoxyphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(ethoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]-bis[(di-3,5-dimethyl-4-methoxyphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(di-3,5-di-tert-butylphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(ethoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(di-3,5-di-tert-butylphenyl)phosphine],

(R)- and (S)-[5,5′-dichloro-6-(methoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis[(di-4-fluorophenyl)phosphine] and

(R)- and (S)-[5,5′-dichloro-6-( ethoxycarbonylmethoxy)-6′-(cyclohexyloxy)biphenyl-2,2′-diyl]bis-[(di-4-fluorophenyl)phosphine],

and also the analogous compounds which are unsubstituted in the 5,5′ positions, and

when there is a sterogenic centre in the radicals bound in the 6 and/or 6′ position, the corresponding compounds having (R) and (S) configurations in the radicals mentioned.

3. A process for preparing a compound according to claim 1 , which comprises:

in a step a) converting a compound of the formula (II)

by ether cleavage into a compound of the formula (III),

in a step b1), reacting the compound of formula (III) with a compound of the formula (IV)

R 3 -Akt  (IV)

in the presence of base to form a compound of the formula (V),

in a step b2), reacting the compound of the formula (V) with a compound of the formula (VI)

R 2 —OOC—B-Akt  (VI)

in the presence of base, to form a compound of the formula (VII),

and, in a step c), reducing the compound of the formula (VII) to a compound of the formula (I), where B, R 1 , R 2 , R 3 , G, R′ and R″ in the formulae mentioned have the same meanings as have been defined under the formula (I) in claim 12 , Akt is halogen or a sulphonate, and R 4 in the formula (II) is C 1 -C 6 -alkyl.

4. A compound of the formula (VII):

wherein:

B is a C 1 -C 4 -alkylene radical which may be singly or multiply substituted by C 1 -C 4 -alkyl;

R 2 is alkyl;

R 3 is alkyl;

G is chlorine or hydrogen; and

R′ and R″ are each, independently of one another, aryl or alkyl.

5. A compound of the formula (V):

wherein:

R 3 is alkyl;

R 1 is hydrogen or C 1 -C 4 -alkyl;

R 2 is alkyl;

G is chlorine or hydrogen; and

R′ and R″ are each, independently of one another, aryl or alkyl.

6. A composition containing a transition metal complex of a compound of the formula (I) according to claim 1 .

7. The composition of claim 6 , wherein the composition is a catalyst composition.

8. A process for preparing an enantiomerically enriched compound which comprises: conducting an asymmetric hydrogenation under conditions sufficient to produce the enantiomerically enriched compound, wherein the hydrogenation is conducted in the presence of a transition metal complex of a compound of the formula (I) according to claim 1 , as catalyst.

9. The process of claim 8 , wherein the amount of catalyst is from 0.001 to 5 mol %.

10. A compound of formula (I) of claim 1 , wherein:

B is CHR 1 ;

R 2 is methyl, ethyl, propyl, isopropyl, n-butyl or tert-butyl;

R 3 is C 1 -C 6 -alkyl; and

R 1 hydrogen or methyl.

11. A compound of formula (I) of claim 1 , wherein:

R′ and R″ are, independently from one another, selected from: C 3 -C 8 -alkyl or C 5 -C 10 -aryl which is unsubstituted, monosubstituted or polysubstituted by radicals selected from the group consisting of chlorine, fluorine, cyano, phenyl, C 1 -C 6 -alkoxy and C 1 -C 6 -alkyl.

12. A compound of formula (I) of claim 1 , wherein:

R′ and R″ are, independently from one another, selected from: cyclopentyl, cyclohexyl, cycloheptenyl, phenyl, o-, m- or p-tolyl, 3,5-dimethylphenyl, 3,5-di-tert-butylphenyl, 3,5-dimethyl-4-methoxyphenyl, 3,5-di-tert-butyl-4-methylphenyl, 4-trifluoromethylphenyl, 4-fluorophenyl, 2-, 3-furyl, 2- or 3-thienyl, 2-N-methylpyffolyl, N-methyl-2-indolyl and 2-thiazolyl.