MULTIFUNCTIONAL CATALYST USEFUL IN THE SYNTHESIS OF CHIRAL...

Details MULTIFUNCTIONAL CATALYST USEFUL IN THE SYNTHESIS OF CHIRAL... MULTIFUNCTIONAL CATALYST USEFUL IN THE SYNTHESIS OF CHIRAL...

2002-03-13

2004-08-24

Bell, Mark L. (Department: 1755)

Catalyst, solid sorbent, or support therefor: product or process

Catalyst or precursor therefor

Organic compound containing

C502S159000, C502S163000, C502S164000, C568S852000, C568S860000, C568S862000, C568S867000, C568S811000, C525S360000, 56, C423S599000

Reexamination Certificate

active

06780810

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a multifunctional reusable catalyst and to a process for the preparation thereof on a single matrix of the support to perform multicomponent reaction in a single pot. More particularly the present invention relates to preparation of multifunctional catalysts consisting of active palladium, tungsten and osmium species useful for the synthesis of chiral vicinal diols by tandem and/or simultaneous reactions involving Heck coupling, N-oxidation and AD reaction of olefins in presence of cinchona alkaloid compounds both as an native one and immobilized one in the said matrix support.
This invention also relates to a process for preparing vicinal diols by asymmetric dihydroxylation of olefins in presence of cinchona alkaloid compounds employing reusable multifunctional catalysts as heterogeneous catalysts in place of soluble osmium catalysts.
BACKGROUND OF THE INVENTION
Products obtained by the dihydroxylation of olefins in presence of cinchona alkaloid compounds are important intermediates for the preparation of drugs and pharmaceuticals. For example the products of cinnamic acid esters are intermediates for taxol side chain. An anticancer drug, diltiazem, calcium antagonist and chloramphenicol can also be derived from the diols obtained through this method.
There are serious disadvantages in performing the catalytic AD reaction with homogeneous system in the manufacture of vicinal diols due to presence of toxic remnants of osmium in products and high cost of osmium tetroxide or potassium osmate dihydrate.
U.S. Pat. Nos. 4,871,855 and 5,260,421 disclose homogeneous asymmetric dihydroxylation of olefins by osmium tetroxide and cinchona alkaloids. The inherent disadvantages in this process are cumbersome procedure for the recovery of the osmium catalyst from the reaction mixture, generation of toxic waste and possibility of presence of toxic osmium in traces in the product.
U.S. Pat. No. 5,516,929 discloses heterogeneous asymmetric dihydroxylation of olefins by osmium tetroxide and polymer-bound cinchona alkaloids. The drawbacks of this process are the difficulty faced in quantitative recovery of toxic osmium catalyst, lower enantioselectivity and reduction in activity and enantioselectivity in each and every recycle experiments.
U.S. Pat. No. 5,968,867 discloses heterogeneous asymmetric dihydroxylation of olefins by osmium tetroxide and silica gel supported bis-cinchona alkaloid derivatives. The drawbacks are difficulty in quantitative recovery of toxic osmium catalyst and reduction in activity and enantioselectivity in each and every recycle experiments.
European patent EP 940,170 A2 discloses catalytic asymmetric dihydroxylation of alkenes using a polymer-supported osmium catalyst. The drawbacks are that higher amount of catalyst (5 mol %), longer reaction time and use of expensive polymer as a support are required.
Reference may be made to a publication J. Am. Chem. Soc. 2001, 123, 1365 wherein asymmetric dihydroxylation of olefins is done by osmium tetroxide and a biomimetic flavin in presence of cinchona alkaloids using H
2
O
2
as oxidant under homogeneous conditions. The inherent disadvantages are difficulty in the recovery of osmium tetroxide and usage of unstable flavin.
OBJECTS OF THE INVENTION
The main object of the invention is to provide reusable multifunctional catalysts useful for the synthesis of chiral vicinal diols.
Another object of the invention is to prepare reusable multifunctional catalysts having transition metal elements such as palladium, osmium and tugsten deposited in a support having interstitial anions such as chloride, nitrate, carbonate, sulfate or calcined material.
Another object of the invention is to prepare reusable multifunctional catalysts on a single matrix of the support to perform multi-component reaction in a single pot.
It is another object of the invention to provide a novel and ecofriendly process for synthesis of chiral diols from aryl halides and olefins in a single pot.
It is another object of the invention to provide a process for the synthesis of chiral diols dispensing with the use of soluble and toxic osmium tetraoxide or potassium osmate dihydrate.
It is another object of the invention to provide a multifunctional catalysts are prepared and used as heterogeneous catalysts for synthesis of chiral diols which precludes the presence of osmium in traces with product.
It is another object of the invention to provide a process for the synthesis of chiral vicinal diols where enantioselectivity and the yields are good and work-up procedure simple.
It is another object of the invention to provide a process for the synthesis of chiral vicinal diols which is economical and environmentally safe without any disposal problem.
SUMMARY OF THE INVENTION
By employing the heterogeneous catalytic system, the cost naturally comes down due to easy recovery of the catalyst and very insignificant loss of osmium tetroxide, when compared with homogenous system. The products thus obtained using heterogeneous catalyst system are also benign since the presence of osmium in minor impurities in the dihydroxylated products is also precluded.
The present invention provides multifunctional catalysts consisting of palladium, osmium and tungsten species in their composition in its homogeneous or heterogeneous form through ion exchange or anchoring for the preparation of vicinal diols which are important intermediates for drugs and pharmaceuticals.
Accordingly the present invention relates to a reusable multifunctional catalyst useful for the preparation of chiral vicinal diols, the said catalyst having formula S—M, wherein S is a support selected from the group consisting of LDH, resin, silica, clay alumina and S′—NR
3
X wherein S′ is a unmodified support selected from resin and silica, R is an alkyl group selected from the group consisting of methyl, ethyl, propyl and butyl, X is selected from the group consisting of Cl, Br, I, F, OH and OAc; and M is an active species comprising two or more different transition metals selected from the group consisting of palladium, ruthenium, osmium, tungsten, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and molybdenum.
In one embodiment of the invention, the active species loading in the catalyst is in the range of 5 to 30% of support.
In another embodiment of the invention, the support as synthesized has an interstitial anion selected from the group consisting of chloride, nitrate, carbonate, sulfate, hydroxide and any mixture thereof.
In another embodiment of the invention, the reusable multifunctional catalyst prepared comprises of LDH-PdOs, resin-PdOs and SiO
2
—PdOs for the synthesis of chiral diols from aryl halides and olefins and SGS-(QN)
2
PHAL-PdOs for the preparation of chiral diols from aryl halides and olefins.
In another embodiment of the invention the reusable multifunctional catalyst prepared comprises of LDH-OsW, resin-OsW, SiO
2
—OsW, SGS-(QN)
2
PHAL-OsW and SGS-(QN)
2
PHAL-OsTi for the synthesis of chiral diols from olefins using H
2
O
2
.
In another embodiment of the invention the reusable multifunctional catalyst prepared comprises of LDH-PdOsW, resin-PdOsW, SiO
2
—PdOsW and SGS-(QN)
2
PHAL-PdOsW for the preparation of chiral diols from aryl halides and olefins using H
2
O
2
.
The present invention also relates to a process for the preparation of reusable multifunctional catalyst useful for the preparation of chiral vicinal diols, the said catalyst having formula S—M, wherein S is a support selected from the group consisting of LDH, resin, silica, clay alumina and S′—NR
3
X wherein S′ is a unmodified support selected from resin and silica, R is an alkyl group selected from the group consisting of methyl, ethyl, propyl and butyl, X is selected from the group consisting of Cl, Br, I, F, OH and OAc; and M is an active species comprising two or more different transition metals selected from the group consisting of palladium, ruthenium, osmium, tungsten, titanium, vanadium, chromium, manganese, iron, cobalt,

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