Organic compounds -- part of the class 532-570 series – Organic compounds – Nitriles
Reexamination Certificate
1999-10-01
2001-06-19
Lambkin, Deborah C. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Nitriles
C549S491000, C556S014000, C568S015000
Reexamination Certificate
active
06248918
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optically active metal complex catalyst compound showing excellent stereoselectivity as it has in its molecule two moieties i.e. a Lewis acid moiety for activating an electrophile and a Lewis base moiety for fixing the position of a nucleophile, an asymmetric ligand compound constituting said catalyst compound, and a method for producing an optically active cyanohydrin compound employing said catalyst compound.
2. Discussion of Background
Optically active substances have been used in many products or intermediates for agricultural chemicals, pharmaceuticals, etc., and the demand for synthesis for optically active substances at an industrially practical level has been increasing year after year.
For the preparation of an optically active substance by an asymmetric reaction, a catalytic asymmetric synthesis is most efficient and industrially superior, whereby a large amount of an optically active substance can be obtained by using a small amount of an asymmetric source.
As such a catalytic asymmetric synthesis, a method has been known wherein a complex having a rare earth element or a Group 13 element (Al or Ga) as the central metal and further containing an alkali metal and a binaphthol as an asymmetric ligand, is used as a catalyst, whereby it has been successful to efficiently synthesize various optically active substances.
It is believed that such a complex exhibits high stereoselectivity, as the central metal serves as a Lewis acid to activate an electrophile, and the alkali metal binaphthoxide moiety serves as a Brønsted base to fix the position of the nucleophile.
Namely, the above complex makes such excellent stereoselectivity possible as it has, in its molecule, two moieties i.e. the Lewis acid moiety for activating the electrophile and the Brønsted base moiety for fixing the position of the nucleophile. However, with respect to an optical active metal complex catalyst having in its molecules two moieties i.e. a Lewis acid moiety for activating the electrophile and a Lewis base moiety for fixing the position of the nucleophile, there has been no report on a product having a high applicability.
On the other hand, with respect to an optically active cyanohydrin compound, many chemical and enzymatic syntheses have been reported, but little has been known with respect to one which is commonly applicable to any type of a substrate to be used.
Especially, nothing has been reported on an efficient asymmetric catalyst containing an aliphatic aldehyde or an aromatic aldehyde as the substrate.
SUMMARY OF THE INVENTION
The present inventors have conducted an extensive study and as a result, have found an optically active metal complex catalyst compound having in its molecule two moieties i.e. a Lewis acid moiety for activating an electrophile and a Lewis base moiety for fixing the position of a nucleophile, and have further found it possible to obtain an optically active cyanohydrin compound from an aldehyde compound in good chemical yield and good optical yield by using such a compound as a catalyst. The present invention has been accomplished on the basis of these discoveries.
Namely, the present invention provides an optically active binaphthyl compound of the formula (1):
wherein R
1
is a C
1-6
alkyl group, an aryl group or an aryl C
1-6
alkyl group, X is an oxygen atom or a sulfur atom, R
2
is a hydrogen atom, a C
1-6
alkyl group, a C
2-6
alkenyl group, a C
2-6
alkynyl group or a halogen atom, each of L
1
and L
2
is a hydrogen atom, or L
1
and L
2
together form MY wherein M is a rare earth element or a Group 13 element, and Y is a C
1-6
alkoxy group, a C
1-6
alkylcarbonyloxy group or a halogen atom, and m is an integer of from 1 to 3.
Further, the present invention provides a method for producing an optically active cyanohydrin compound of the formula (3):
wherein R
3
is a C
1-6
alkyl group, an aryl group, an aryl C
1-6
alkyl group, a C
2-6
alkenyl group, an aryl C
2-6
alkenyl group, a C
2-6
alkynyl group, an aromatic heterocyclic group or a non-aromatic heterocyclic group, which comprises reacting an aldehyde compound of the formula (2):
R
3
CHO (2)
wherein R
3
is as defined above, with trimethylsilylcyanide in the presence of the optically active compound of the formula (1) wherein L
1
and L
2
together form MY wherein M and Y are as defined above.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the present invention will be described in detail.
Firstly, terms used for the substituents of R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, m, X, L
1
and L
2
, will be described.
In this specification, “n” means normal, “i” iso, “s” secondary, “t” tertiary, “c” cyclo, “o” ortho, “m” meta, “p” para, “Et” ethyl, “Bu” butyl, “Oct” octyl, “Ph” phenyl, “Ms” methanesulfonyl, “Ts” p-toluenesulfonyl, and “MOM” methoxymethyl.
The rare earth element includes lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Y) and lutetium (Lu).
The Group 13 element includes aluminum (Al) and gallium (Ga).
The C
1-6
alkyl group includes, for example, a methyl group, an ethyl group, a n-propyl group, an i-propyl group, a c-propyl group, a n-butyl group, an i-butyl group, a s-butyl group, a t-butyl group, a c-butyl group, a n-pentyl group, a 2-pentyl group, a 3-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a c-pentyl group, a n-hexyl group, a 2-hexyl group, a 3-hexyl group, a c-hexyl group, a 1-methyl-1-ethyl-n-propyl group, a 1,1,2,-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group and a 3,3-dimethyl-n-butyl group. The C
1-8
alkyl group includes, for example, a n-heptyl group and a n-octyl group, in addition to the above alkyl groups.
The C
2-6
alkenyl group includes, for example, an ethenyl group, a 1-propenyl group, a 2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 3-hexenyl group, a 4-hexenyl group and a 5-hexenyl group.
The C
2-6
alkynyl group includes, for example, an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-pentynyl group, a 2-pentynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 2-hexynyl group, a 3-hexynyl group, a 4-hexynyl group and a 5-hexynyl group.
The C
1-6
alkoxy group includes, for example, a methoxy group, an ethoxy group, a n-propoxy group, an i-propoxy group, a c-propoxy group, a n-butoxy group, an i-butoxy group, a s-butoxy group, a t-butoxy group, a c-butoxy group, a n-pentyloxy group and a n-hexyloxy group. The C
1-6
alkylcarbonyloxy group includes, for example, a methylcarbonyloxy group, an ethylcarbonyloxy group, a n-propylcarbonyloxy group, an i-propylcarbonyloxy group, a n-butylcarbonyloxy group, an i-butylcarbonyloxy group, a s-butylcarbonyloxy group, a t-butylcarbonyloxy group, a 1-pentylcarbonyloxy group, a 2-pentylcarbonyloxy group, a 3-pentylcarbonyloxy group, a i-pentylcarbonylxoy group, a neopentylcarbonyloxy group, a t-pentylcarbonyloxy group, a 1-hexylcarbonyloxy group, a 2-hexylcarbonyloxy group, a 3-hexylcarbonyloxy group, a 1-methyl-n-pentylcarbonyloxy group, a 1,1,2-trimethyl-n-propylcarbonyloxy group, a 1,2,2-trimethyl-n-propylcarbonyloxy group and a 3,3-dimethyl-n-butylcarbonyloxy group.
The aryl C
2-6
alkenyl group includes, for example, a 1-phenylethenyl group, a 2-phenylethenyl group, a 1-phenyl-1-propenyl group, a 2-phenyl-1-propenyl group, a 3-phenyl-1-propenyl group, a 1-phenyl-2-propenyl group, a 2-phenyl-2-propenyl group, a 3-phenyl-2-propenyl group, a 1-phenyl-1-butenyl group, a 2-phenyl-1-butenyl group, a 3-phenyl-1-butenyl group, a 4-phenyl-1-butenyl group, a 1-phenyl-2-butenyl group, a 2-phenyl-2-butenyl group, a 3-phenyl-2-butenyl group, a 4-phenyl-2-butenyl group, a 3-phenyl-3-butenyl group, a 2-
Hamashima Yoshitaka
Kanai Motomu
Shibasaki Masakatsu
Lambkin Deborah C.
Nissan Chemical Industries Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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