Single oxygen catalysts including condensed carbon molecules

Details Single oxygen catalysts including condensed carbon molecules Single oxygen catalysts including condensed carbon molecules

2002-04-19

2004-10-19

Bell, Mark L. (Department: 1755)

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

Catalyst or precursor therefor

Organic compound containing

C502S159000, C502S162000, C502S167000, C502S168000, C502S180000, C548S417000, C436S526000

Reexamination Certificate

active

06806223

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to singlet oxygen catalysts including core materials coated with condensed carbon molecules such as fullerenes and the use of these materials for the production of specialty chemicals.
BACKGROUND OF THE INVENTION
Polymer beads coated with dyes such as Rose Bengal have been made and used to photo-catalyze reactions in organic solvents as described in U.S. Pat. No. 4,315,998 to Neckers et al. While the dye coated molecules described appear to be effective for certain photo-catalyzing reactions in solvents, these dyed molecules do not have the convenient functionality for covalently bonding other molecules. As such, dye coated polymer beads cannot be effectively modified to perform stereoselective
1
O
2
oxidations as set forth in accordance with the teachings of the present invention. Further, fullerenes have both excellent stability and a high quantum efficiency for
1
O
2
formation, which makes fullerene coated catalysts very stable.
Certain other catalysts have been reported as being capable of photo-catalytic reactions in water. According to an article appearing in the J. Am. Chem. Soc., Vol. 101, pgs. 4016-4017 authored by A. P. Schapp et al., a more hydrophilic bead was made by copolymerization of 3-cholomethylstryene, 4-cholomethylstryene, ethylene glycol dimethacrylate and ethylene glycol monomethacrylate. Rose Bengal was then attached to this bead and shown to form
1
O
2
in water.
Still another aqueous photo-catalyst was described in an article by F. Prat et al. appearing in Photochemical Photobiol., Vol. 67, pgs. 626-627. According to this article, a bead linked to an amino group by a long poly(ethylene glycol) chain was functionalized with Rose Bengal and used to form
1
0
2
in water.
While the above mentioned photo-catalysts appear useful, the aqueous catalysts tend to be difficult to make or do not have convenient functionality at the outermost layer necessary for covalently bonding other molecules.
More recently, polymeric beads have been demonstrated as being coatable with fullerenes and fullerene derivatives as described in U.S. Pat. No. 5,308,481. According to this patent, a fullerene derivative was made according to a three step process involving reduction of the fullerene, addition of bromine to a double bond and replacement of one of the fullerene bromines with 8-bromo-1-octanol. This derivative was then added to an amine coated polymer bead by displacement of a tethered bromine. While this method does involve addition of an amine to a derivatized fullerene, the process involves three additional steps, none of which are trivial. The process described in the present invention represents a significant improvement on the mode of attaching fullerenes to beads. Other attachment modes are also briefly described at the end of the '481 patent described in accordance with the teachings of the present invention.
Research has additionally shown that fullerenes placed on films can be used to photochemically form singlet oxygen. However, films lack sufficient surface area to be able to make enough
1
O
2
for the materials to be used effectively as catalyst materials.
Singlet oxygen is commonly used as an oxidizing agent in organic synthesis and is an essential component in the production of photo-dynamic therapy for the treatment of cancer.
SUMMARY OF THE INVENTION
The need for catalysts which can be used to produce complex chemical compounds in an environmentally friendly way are in great demand. For example, pharmaceutical companies spend billions of dollars annually preparing drugs as the demand for new drugs continues to rise. However, it is well recognized that pharmaceutical companies are required to spend enormous funds on research and development just to get a drug to market. Thus, there is an ever increasing need for low cost, effective drug precursors which can help reduce research costs and ultimately lower a drug's costs.
According to the teachings of the present invention, certain core materials can be coated with condensed carbon molecules such as fullerenes having available functional groups for covalently adding hydrophilic components, thus allowing singlet oxygen
1
O
2
reactions to be carried out in water or selective solvents. In particular, derivatized or underivatized condensed carbon molecules can be utilized to coat polymeric resin beads, glass beads or dendrimers to form catalysts and precursor components for stereoselective or regioselective reactions, by way of non-limiting example. By the phrase “condensed carbon molecules” it is meant that a variety of normally hollow carbon molecules such as fullerenes (namely C
32
, C
60
, C
70
and C
84
) and carbon nanotubes which have a high quantum efficiency for the formation of singlet oxygen may be employed.


REFERENCES:
patent: 4315998 (1982-02-01), Neckers et al.
patent: 5153166 (1992-10-01), Jain et al.
patent: 5294732 (1994-03-01), Chiang et al.
patent: 5308481 (1994-05-01), Stalling et al.
patent: 5367051 (1994-11-01), Narang et al.
patent: 5382718 (1995-01-01), Bekiarian et al.
patent: 5386048 (1995-01-01), West et al.
patent: 5904852 (1999-05-01), Tour et al.
patent: 6162926 (2000-12-01), Murphy et al.
patent: 6319674 (2001-11-01), Fulcrand et al.
patent: 6359061 (2002-03-01), Swayze et al.
patent: 6362011 (2002-03-01), Massey et al.
patent: 6380266 (2002-04-01), Katz et al.
patent: 6448412 (2002-09-01), Murphy et al.
Daniel Latassa, Olivier Enger, Carlo Thilgen, Tilo Habicher, Heribert Offermans, Francois Diederich, “Polysiloxane-supported fullerene derivative as a new heterogeneous sensitiser for the selective photooxidation of sulfides to sulfoxides by1O2”.Journal of Materials Chemistry, 2002, vol. 12, pp. 1993-1995.

Affiliated with

Also associated with

Rating

Single oxygen catalysts including condensed carbon molecules does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Single oxygen catalysts including condensed carbon molecules, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Single oxygen catalysts including condensed carbon molecules will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3280428