Novel ligand catalyst systems formed by reaction of carbonyl compounds with organosilicon compounds

A novel catalyst system useful in preparation of dimethyl carbonate is prepared by complexing a metal salt such as cupric chloride CuCl.sub.2 with a ligand formed by reacting a carbonyl-containing organic compound such as ethyl formate with an organosilicon compound containing alkoxy and amine fucntionality, such as 3-aminopropyltriethoxysilane.

FIELD OF THE INVENTION 
This invention relates to novel ligand catalyst systems. More particularly 
it relates to complexed metals bonded to inorganic oxide supports. 
BACKGROUND OF THE INVENTION 
The art of immobilizing various materials on solid supports permits 
attainment of the advantages of both homogeneous catalysts and 
heterogeneous catalysts. Illustrative of prior art directed to this art 
are (i) R. B. Merrifield J. Am. Chem. Soc. 85 2149 (1963); (ii) U.S. Pat. 
No. 3,709,855; (iii) D.D. Whitehurst, CHEMTECH 44 (1980), (iv) P. Tundo et 
al J. Am. Chem. Soc. 101, 6606 (1979); (v) U.S. Pat. No. 3,980,583; etc. 
It is an object of this invention to provide a novel ligand catalyst 
system. Other objects will be apparent to those skilled in the art. 
STATEMENT OF THE INVENTION 
In accordance with certain of its aspects, this invention is directed to a 
process which comprises reacting in liquid phase: 
##STR1## 
wherein R and R" are hydrogen, alkyl, alkaryl, aralkyl, cycloalkyl, or 
aryl, R' is alkylene, alkarylene, aralkylene, cycloalkylene, or arylene, 
R'" is alkyl, aryl, or cycloalkyl, and n is an integer 0,1, or 2, with 
(ii) a carbonyl-containing organic compound selected from the group 
consisting of carboxylic acids, carboxylic acid esters, ketones, 
aldehydes, and acid anhydrides thereby forming product 
##STR2## 
wherein G is a residue of said carbonyl-containing organic compound bonded 
to said nitrogen atom N through a carbon atom. 
In accordance with certain of its other aspects, this invention is directed 
to a novel catalyst comprising 
(i) an inert oxide substrate bearing on the surface thereof (ii) at least 
one residue 
##STR3## 
wherein 
R" is hydrogen, alkyl, alkaryl, aralkyl, cycloalkyl, or aryl; 
R' is alkylene, alkarylene, aralkylene, cycloalkylene, or arylene; 
R'" is alkyl, alkaryl, aralkyl, cycloalkyl or aryl; 
n is an integer 0, 1, or 2, 
G is a residue of a carbonyl-containing organic compound; and 
bonded thereto a metal salt. 
DESCRIPTION OF THE INVENTION 
The compound which may be used to form the ligands of this invention may be 
characterized by the formula 
##STR4## 
wherein R and R" are selected from the group consisting of hydrogen, 
alkyl, alkaryl, aralkyl, cycloalkyl, and aryl, R'" is alkyl, aryl, or 
cycloalkyl, R' is a hydrocarbon selected from the group consisting of 
alkylene, alkarylene, aralkylene, cycloalkylene, and arylene; and n is an 
integer 0, 1, or 2. 
When R or R" or R'" is alkyl, it may typically be methyl, ethyl, n-propyl, 
iso-propyl, n-butyl, i-butyl, sec-butyl, amyl, octyl, decyl, octadecyl, 
etc. When R or R", or R'" is aralkyl, it may typically be benzyl, 
betaphenylethyl, etc. When R or R" or R'" is cycloalkyl, it may typically 
be cyclohexyl, cycloheptyl, cyclooctyl, 2-methylcycloheptyl, 
3-butylcyclohexyl, 3-methylcyclohexyl, etc. When R or R" or R'" is aryl, 
it may typically be phenyl, naphthyl, etc. When R or R" is alkaryl, it may 
typically be tolyl, xylyl, etc. R or R" or R'" may be inertly substituted 
i.e. it may bear a non-reactive substituent such as alkyl, aryl, 
cycloalkyl, etc. The preferred groups may be lower alkyl, i.e. C.sub.1 
-C.sub.10 alkyl, groups (or groups derived therefrom) including e.g. 
methyl, ethyl, n-propyl, i-propyl, butyls, amyls, hexyls, octyls, decyls, 
etc. R may preferably be ethyl; R' may preferably be propylene 
(CH.sub.2).sub.3. 
Illustrative silicon compounds which may be employed may be the following: 
TABLE 
3-aminopropyl triethoxy silane 
N-(2-aminoethyl-3-aminopropyl) trimethoxy silane 
3-aminopropyl trimethoxy silane 
The preferred compound may be 3-aminopropyl triethoxy silane in which R is 
ethyl, R' is propylene (CH.sub.2).sub.3, and n is zero. These compounds 
may be available commercially or they may be readily prepared. 
The carbonyl-containing organic compounds, which may be reacted with the 
organosilicon compounds in practice of the process of this invention, may 
be typified by those containing the following functionality: carboxylic 
acid, carboxylic acid ester, ketone, aldehyde, acid anhydride, etc. 
Illustrative carbonyl-containing organic compounds which may be employed 
may be the following: 
TABLE 
acetic acid 
benzoic acid 
TABLE 
ethyl formate 
ethyl acetoacetate 
TABLE 
2,4-pentanedione 
2,6-hexanedione 
TABLE 
salicylaldehyde 
acetaldehyde 
TABLE 
succinic anhydride 
phthallic anhydride 
The reaction between the organometal compound and the carbonyl-containing 
organic compounds in practice of the process of this invention may be 
carried out by use of 0.1-10 moles, say 1 mole of carbonyl-containing 
compound per mole of silcon compound. 
The reaction may be carried out in the presence of solvent if desired, 
typically lower alcohols such as ethanol or hydrocarbons such as hexane. 
Preferrably reaction is carried out in liquid phase at 0.degree. 
C.-150.degree. C., say 0.degree. C. and atmospheric pressure by adding one 
reactant, typically the organometal compound, slowly with agitation over 
5-120 minutes to the carbonyl-containing organic compound. 
After addition is complete, the reaction mixture is heated to reflux, 
typically 50.degree. C.-150.degree. C., say 70.degree. C. for 1-24 hours, 
say 3 hours. At the conclusion of the reaction, the solvent may be 
recovered by distillation and the excess of carbonyl-containing compound 
may also be similarly removed. 
The ligands so prepared may be recovered as high boiling liquids. Typical 
of the reactions may be the following. 
##STR5## 
Illustrative products which may be prepared include the following: 
TABLE 
______________________________________ 
A. (EtO).sub.3 Si(CH.sub.2).sub.3 NHCHO 
B. 
##STR6## 
C. 
##STR7## 
D. 
##STR8## 
E. 
##STR9## 
F. 
##STR10## 
______________________________________ 
It is a feature of the process of this invention that it is possible to 
bond these ligands to the surface of inorganic oxide substrates or 
supports, which are characterized by the presence of pendent surface 
hydroxyl groups. 
The charge solid inorganic oxides which may be used as substrates in 
practice of the process of this invention may include a wide variety of 
porous refractory oxides typified by those which may commonly be used as 
inert catalyst supports. Although they may be used in impure form or as 
mixtures, more consistent results may be attained by the use of one 
species of pure porous refractory metal oxide. Illustrative of the porous 
refractory solid inorganic metal (including metalloid) oxides may be 
oxides of boron, magnesium, aluminum, silicon, phosphorus, calcium, 
titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, 
zinc, arsenic, cadmium, barium, etc. It will be apparent that certain 
oxides typified by those of sodium may be too active under reaction 
conditions and may not be employed. Others may be too expensive. The 
preferred solid refractory oxides are those commonly referred to as inert 
and which have heretofore been proposed for use as catalyst supports. Most 
preferred are aluminum oxide (Al.sub.2 O.sub.3) and silicon dioxide 
(SiO.sub.2). Complex oxides may be employed viz: silica-magnesia; etc. It 
will be apparent that silicon is frequently referred to as a metalloid; 
but it is intended to be embraced within the term "metal" as used herein; 
and in fact silicon dioxide is a preferred charge solid inorganic porous 
refractory metal oxide. A preferred form of silica is that referred to as 
silica gel. 
It is also possible to use as substrates refractory oxides wich are 
crystalline aluminosilicates including synthetic zeolites typified by 
zeolites X, Y, ZSM-4, ZSM-5, ZSM-11, ZSM-21, etc. as well as naturally 
occurring zeolites such as erionite, faujasite, mordenite, etc. 
The surface of the charge porous refractory inorganic metal oxide bears a 
plurality of pendant hydroxyl groups. Although it may be possible to use 
the porous refractory oxides as they are obtained, it is preferred to 
pretreat them preferably by heating to drive off adsorbed 
water, at 50.degree. C.-450.degree. C., say 200.degree. C. for 1-24 hours, 
say 6 hours at atmospheric pressure. In the case of silica, it may 
alternatively be desirable to pretreat by reaction in aqueous medium in 
liquid phase with a Bronsted acid, typically at 25.degree. C.-100.degree. 
C., say 100.degree. C. for 1-24 hours, say 4 hours. Illustrative Bronsted 
acids include hydrogen halides, preferably hydrogen chloride. 
During this pretreatment, it appears that additional hydroxyl groups may be 
made available for reaction. Pretreatment is not necessary however. 
In practice of the preferred mode of carrying out the process of this 
invention, the ligand which has been formed from the organosilicon silicon 
compound and the carbonyl-containing organic compound is reacted with a 
metal salt. 
Typical metal salts may be salts of metals of Group IB (Ag or Au or 
preferably Cu) or of Group VIII (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt). 
The metal salts may already have ligands attached to them--ionic, neutral, 
or mixed--typified by ammonia, phosphine, carbon monoxide, olefins, etc. 
The anion may preferably be halide (fluoride, chloride, bromide, or 
iodide), halogen-like (cyanide, cyanate, thiocyanate) etc, or others 
typified by nitrate, sulfate, phosphate, sulfide, carbonate, or 
carboxylate, (either acidic, basic, or neutral). 
Illustrative salts may include (the first four being preferred): 
TABLE 
Cu.sub.2 Cl.sub.2 
CuC.sub.12 
FeCl.sub.12 
PdCl.sub.2 
NiCl.sub.2 
CuCl (OCH.sub.3) 
CuBr.sub.2 
CuSO.sub.4 
RhCl.sub.3 
RuI.sub.3 
Reaction, in the preferred embodiment, between the metal salt and the 
ligand is preferably effected by addition of one mole of the former 
(dissolved in solvent such as absolute ethanol) to 0.01-10 moles, say 1 
mole of the latter (also dissolved in solvent such as absolute ethanol). 
Reaction is effected at -50.degree. C. to 50.degree. C., say 20.degree. C. 
and preferably atmospheric pressure over 5-180 minutes, say 60 minutes. 
At the end of this reaction period, there is added hydrocarbon solvent 
(preferably toluene) in amount of 50-10,000 ml, say 500 ml per mole of 
ligand and there is also added inorganic oxide in amount of 1-5000 g, say 
700 g per mole of ligand. 
The mixture is heated to reflux at 50.degree. C. -150.degree. C., say 
100.degree. C. for 5-600 minutes, say 240 minutes during which distillate 
is removed and replaced with an equivalent amount of e.g. toluene. The 
procedure is repeated twice during which total time of reflux of 4 hours, 
the toluene-alcohol azeotrope is removed to drive the reaction to 
completion. 
The mixture is cooled to ambient temperature of 20.degree. C.-30.degree. 
C., say 25.degree. C. and filtered--the solid being washed with fresh 
toluene and then with ethanol. Product after drying at room temperature 
under vacuum is typically a colored powder obtained in yield of 80-100%, 
say 90% based on charged reactants. 
In practice of the process of this invention, it is possible to form the 
desired product by any of the following routes: 
(i) reacting the amine A with the carbonyl-compound B to form the ligand, 
then reacting this with the support C to form the immobilized ligand, and 
then reacting with the metal salt D to form the immobilized metal 
complex--viz ABCD; 
(ii) reacting the organosilicon amine A with the carbonyl-compound B and 
the metal salt D (in two steps or preferably one step) to form a preformed 
complex and then reacting with the support C to form the immobilized metal 
complex--viz ABDC; 
(iii) adding all the ingredients to the reaction vessel simultaneously; 
(iv) reacting the organosilicon amine A with the support C, then reacting 
with the carbonyl compound B, followed by reacting with the metal salt 
D--viz ACBD. 
Other equivalent variants will be apparent to those skilled in the art. 
Although the order of addition of the several components may be modified, 
it is preferred that the ligand be formed first by reaction of 
organosilicon compound A and carbonyl-containing organic compound B, then 
this be reacted with metal salt D and then the solid oxide C be added e.g. 
the ABDC sequence. 
The product of this invention according to certain of its aspects may be a 
complex of a metal salt with an inorganic oxide bearing immobilized 
thereon a ligand of a carbonyl-containing organic compound and a primary 
or secondary amine of an organosilicon-bond-forming atom. 
Typical of these products may be the following: 
TABLE 
__________________________________________________________________________ 
Carbonyl-Ctg 
Compound Amine Metal Salt 
Inorganic Oxide 
__________________________________________________________________________ 
Ethyl Formate 
3-aminopropyl triethoxy silane 
CuCl.sub.2 
SiO.sub.2 
Ethyl Formate 
N--(2-aminoethyl-3-aminopropyl) 
trimethoxy silane 
FeCl.sub.2 
SiO.sub.2 
Ethyl Acetoacetate 
3-aminopropyltriethoxy silane 
PdCl.sub.2 
SiO.sub.2 
2,4-pentanedione 
" NiCl.sub.2 
SiO.sub.2 
salicylaldehyde 
" CuCl.sub.2 
Al.sub.2 O.sub.3 
succinic anhydride 
" CuCl.sub.2 
TiO.sub.2 
Ethyl Formate 
N--(2-aminoethyl-3 aminopropyl) 
CuCl(OCH.sub.3) 
SiO.sub.2 
trimethoxy silane 
__________________________________________________________________________ 
It is a feature of the process of this invention that these novel products 
may be used as catalysts for various reactions depending upon the specific 
composition. They may be found to be useful in oxidative carbonylation 
reactions typified by the preparation of dimethyl carbonate from methanol. 
A preferred embodiment may be that last set forth in the above table. 
In a typical oxidative carbonylation, the charge e.g. methanol may be added 
to a reaction vessel with the catalyst and, after flushing with carbon 
monoxide, pressured to 100-5000 psig, say 1000 psig with carbon monoxide 
at 0.degree. C.-50.degree. C., say 25.degree. C. 
The reaction mixture may be maintained at 50.degree. C.-125.degree. C., say 
100.degree. C. for 1-24 hours, say 8 hours with agitation. After cooling 
to ambient temperature, the reaction mixture, analyzed by gas 
chromatography (using isooctane as an internal standard), is found to 
contain dimethyl carbonate in yield (based on methanol) of 18%-36%, say 
36% using CuCl.sub.2. 
In the absence of ligands or supports, CuCl.sub.2 gives yields of dimethyl 
carbonate of ca 12% or less. 
It is a feature of the process of this invention that yield of product in 
the oxidative carbonylation reaction may be substantially increased if the 
metal salt, employed in a lower valence state, is oxidized to a higher 
valence state in the presence of the charge which is to be oxidatively 
carbonylated. 
In one preferred embodiment, the catalyst may be formed from cuprous 
chloride (e.g. an immobilized cuprous chloride complex of silicon dioxide 
bearing immobilized thereon a ligand of ethyl formate and 
N-(2-aminoethyl-3-aminopropyl) trimethoxysilane). 
This valent catalyst may be added to the reaction vessel together with 
solvent (preferably methanol). The cuprous ion may be oxidized as by 
passing dry air 
through the reaction mixture at 0.degree. C.-50.degree. C., say 45.degree. 
C. for 1-24 hours say 6 hours. The oxidized catalyst is then flushed with 
carbon monoxide and pressured to 100-2000 psig, say 1000 psig at ambient 
temperature and heated to 50.degree. C.-125.degree. C., say 100.degree. C. 
for 1-24 hours, say 8 hours. After cooling, analysis by gas chromatogrophy 
(using isooctane as an internal standard) showed attainment of a yield, 
based on copper salt charged, of 33%-69%, say 69%. 
It is a particular feature of the process of this invention that it may be 
carried out in a continuous manner. In this continuous process, the 
catalyst may for example be a complex (prepared from cuprous chloride 
Cu.sub.2 Cl.sub.2, with silicon dioxide on which is immobilized a ligand 
of ethyl formate and 3-aminopropyl triethoxy silane) in the form of a 
packed bed of particles of about 5-6 mm diameter. 
Air may be passed upwardly through the bed. Reaction is carried out at 
50.degree. C.-125.degree. C., say 90.degree. C. and 300-1500 psig, say 600 
psig. 
As these compounds pass through the catalyst bed, the carbon monoxide and 
the methanol react in liquid phase to form dimethyl carbonate in the 
presence of oxygen: 
##STR11## 
It also appears that the metal salt (e.g. copper (I) chloride) may 
participate in the reaction as follows (L* represents the supported 
ligand): 
##STR12## 
Product withdrawn from the reactor includes dimethyl carbonate and water. 
Anhydrous dimethyl carbonate may be obtained by distillation. 
Dimethyl carbonate may be employed as an additive to hydrocarbon fuels 
including gasolines; and it also finds use as an intermediate in many 
chemical reactions wherein it may replace phosgene.

DESCRIPTION OF SPECIFIC EMBODIMENTS 
Practice of the process of this invention will be apparent to those skilled 
in the art from the following examples. 
All reactions were carried out using reagent grade materials with no prior 
purification. The catalysts were routinely prepared under an inert 
atmosphere. 
CATALYST PREATION - LIGAND FORMATION 
Example I 
Amide Ligand. Reaction of 3-Aminopropyltriethoxysilane with ethyl formate. 
A reaction flask containing 220 ml (2.73 mol) ethyl formate was cooled to 
0.degree. C. in an ice bath; and 3-aminopropyltriethoxy silane (120 g, 
0.54 mol) was added slowly with stirring. After complete addition the 
mixture was heated at reflux for ten hours. The excess ethyl formate was 
stripped from the product on a rotary evaporator at room temperature under 
vacuum to afford 147 g of an orange liquid. Infrared (IR) and nuclear 
magnetic resonance (NMR) spectroscopy were consistent with the proposed 
amide ligand structure. 
Example II 
Diamide Ligand. Reaction of N-(2-aminoethyl-3-aminopropyl) trimethoxysilane 
with ethyl formate. 
To a flask containing 150 ml (1.86 mol) ethyl formate cooled as in Example 
I was added 30 g (0.14 mol) N-(2-aminoethyl-3-aminopropyl) 
trimethoxysilane. After ten hours at reflux, the excess ethyl formate was 
removed by stripping as in Example I to yield 39 g of a yellow liquid. 
Both IR and NMR analyses were consistent with the proposed structure. 
Example III 
Enaminone Ligand. Reaction of 3-Aminopropyltriethoxy silane with ethyl 
acetoacetate. 
Into a flask containing a stirrer, addition funnel and Dean Stark trap with 
reflux condenser was added 15 g (0.12 mol) ethyl acetoacetate, 25 ml 
absolute ethanol, and 150 ml heptane. While stirring, 25 g (0.11 mol) 
3-aminopropyltriethoxy silane was added slowly at room temperature. After 
complete addition, the mixture was heated at reflux for 3 hours with 
continuous removal of the bottom layer that was collected in the 
Dean-Stark trap (19 ml, calc. 2.8 ml water, 0.16 mol). The resulting 
mixture was stripped of residual solvent at 50.degree. C. under vacuum to 
afford 37 g of a pale yellow liquid. Both IR and NMR analyses were 
consistent with the proposal structure. 
Example IV 
Enaminone Ligand. Reaction of 3-aminopropyltriethoxy silane with 2,4 
Pentanedione. 
Into a flask fitted as in Example III was added 11 g (0.11 mol) 
2,4-pentanedione, 25 ml absolute ethanol, and 150 ml heptane. While 
stirring, 25 g (0.11 mol) 3-aminopropyltriethoxysilane was added slowly at 
room temperature. The mixture was heated to reflux for 3 hours removing 13 
ml of the bottom azeotropic layer (calc. 2 ml water, 0.11 mol). Stripping 
at 50.degree. C. under vacuum yielded 31 g of a brown liquid. Both IR and 
NMR analyses were consistent with the proposed structure. 
Example V 
Schiff Base Ligand. Reaction of 3-aminopropyltriethoxy silane with 
salicylaldehyde. 
Into a flask fitted as in Example III was added 14 g (0.11 mol) 
salicylaldehyde, 25 ml absolute ethanol, and 150 ml heptane. While 
stirring, 25 g (0.11 mol) 3-aminopropyltriethoxysilane was added slowly at 
room temperature. The mixture was heated to reflux for 3 hours removing 16 
ml of the bottom azeotropic layer (calc. 2.4 ml water, 0.13 mol). 
Stripping at 50.degree. C. under vacuum yielded 36 g of a brown liquid. 
Both IR and NMR analyses were consistent with the proposed structure. 
Example VI 
Amide-Acid Ligand. Reaction of 3-aminopropyltriethoxy silane with succinic 
anhydride. 
Into a flask fitted as in Example III was added 11 (0.11 mol) succinic 
anhydride, 25 ml. absolute ethanol, and 150 ml heptane. While stirring, 25 
g (0.11 mol) 3-aminopropyltriethoxy silane was added slowly at room 
temperature. The mixture was heated at reflux for 3 hours with no 
formation of a lower azeotropic layer. Stripping at 50.degree. C. under 
vacuum afforded 39 g of a viscous yellow liquid. Both IR and NMR analyses 
were consistent with the proposed structure. 
CATALYST PREATION - METAL COMPLEXATION 
Example VII 
Copper Salt. Reaction of Cupric Chloride with product of Example I and 
attachment to Silica Gel. 
Into a flask fitted with an addition funnel, Dean Stark trap and stirrer 
was added 6.8 g (0.027 mol) of the product of Example I and 25 ml absolute 
ethanol. Cupric chloride (2.1 g, 0.016 mol) was dissolved in 25 ml 
absolute ethanol and this solution added slowly to the pot at room 
temperature. After addition the mixture was stirred one hour at room 
temperature. Toluene (150 ml) was added along with 20 g silica gel. The 
solution was heated at reflux for one hour and 25 ml distillate was 
removed. Fresh toluene (25 ml) was added to the pot and the procedure 
repeated 3 more times (Total-4 hours reflux, 100 ml distillate removed, 
100 ml fresh toluene added). After cooling, the mixture was filtered and 
the solid washed slowly with fresh toluene (50 ml) and then with ethanol 
(50 ml). The solid was then dried at room temperature under vacuum to 
yield a yellow powder, 26 g, which contained 7.71 percent carbon, 1.38 
percent nitrogen and 2.27 percent copper. 
Example VIII 
Iron Salt. Reaction of Ferrous Chloride with product of Example I and 
attachment to Silica Gel. 
The procedure of Example VII was followed with 2.0 g (0.06 mol) ferrous 
chloride (FeCl.sub.2). Drying at room 2.0 g (0.06 mol) temperature under 
vacuum afforded a light orange powder (28.8 g) containing 5.10 percent 
carbon, 1.26 percent nitrogen, and 2.4 percent iron. 
Example IX 
Palladium Salt. Reaction of Palladium Chloride with product of Example I 
and attachment to Silica Gel. 
The procedure of Example VII was followed with 2.8 g (0.016 mol) palladium 
chloride (PdCl.sub.2). Drying at room temperature under vacuum afforded a 
dark brown powder (27.6 g) containing 4.96 percent carbon, 1.32 percent 
nitrogen, and 2.3 percent palladium. 
Example X 
Nickel Salt. Reaction of Nickel Chloride with product of Example I and 
attachment to Silica gel. 
The procedure of Example VII was followed with 3.7 g (0.016 mol) nickel 
chloride hexahydrate (NiCl.sub.2.6H.sub.2 O). Drying at room temperature 
under vacuum afforded a light green powder (31.1 g) containing 5.09 
percent carbon, 1.24 percent nitrogen, and 2.5 percent nickel. 
Example XI 
Copper Salt. Reaction of Cupric Chloride with product of Example II and 
attachment to silica gel. 
The procedure of Example VII was followed using 34 g (0.12 mol) catalyst 
from Example II, 75 ml ethanol, 100 g silica gel and 21 g (0.16 mol) 
cupric chloride. Drying at room temperature under vacuum afforded 152 g of 
a gold powder containing 7.91 percent carbon, 1.93 percent nitrogen, and 
5.2 percent copper. 
Example XII 
Copper Salt. Reaction of Cupric Chloride with product of Example III and 
attachment to silica gel. 
Into a flask fitted as in Example VII was added 9 g (0.027 mol) of the 
product of Example III and 25 ml absolute ethanol. A mixture of cupric 
chloride (3.6 g, 0.027 mol) in 25 ml absolute ethanol was added slowly 
over 30 minutes. After stirring at room temperature for one hour, toluene 
(150 ml) and silica gel (20 g) were added and the procedure followed as in 
Example VII. Drying at room temperature under vacuum afforded 26 g of a 
dark green powder containing 6.27 percent carbon, 1.0 percent nitrogen and 
5.0 percent copper. 
Example XIII 
Copper Salt. Reaction of Cupric Chloride with product of Example IV and 
attachment to Silica Gel. 
Into a flask fitted as in Example VII was added 8.2 g (0.027 mol) Example 
IV and 25 ml absolute ethanol. Cupric chloride (3.6 g, 0.027 mol) in 
ethanol (25 ml) was added slowly and the procedure of Example VII was 
followed using toluene and silica gel (20 g). Drying at room temperature 
under vacuum afforded 26 g of a dark gold powder containing 6.99 percent 
carbon 0.96 percent nitrogen, and 4.5 percent copper. 
Example XIV 
Copper Salt. Reaction of Cupric Chloride with product of Example V and 
attachment to silica gel. 
Into a flask fitted as in Example VII containing 8.8 g (0.027 mol) Example 
V and 25 ml ethanol was added 3.6 g (0.027 mol) cupric chloride in 25 ml 
ethanol. The procedure of Example VII was followed using toluene and 
silica gel (20 g). Drying at room temperature under vacuum yielded 27 g of 
a brown powder containing 9.21 percent carbon, 1.18 percent nitrogen, and 
4.9 percent copper. 
Example XV 
Copper Salt. Reaction of Cupric Chloride with product of Example VI and 
attachment to silica gel. 
Into a flask fitted as in Example VII containing 8.6 g (0.027 mol) Example 
VI and 25 ml ethanol was added 3.6 g (0.027 mol) cupric chloride in 25 ml 
ethanol. The procedure of Example VII was followed using toluene and 
silica gel (20 g). Drying at room temperature under vacuum afforded 25 g 
of a gold powder containing 8.58 percent carbon, 1.13 percent nitrogen, 
and 2.1 percent copper. 
Example XVI 
Copper Salt. Reaction of Cupric Chloride with product of Example IV and 
attachment to titanium dioxide. 
The procedure of Example XIII was followed using 20 g titanium dioxide 
instead of silica gel. The dried light brown powder (22 g) contained 2.81 
percent carbon, 0.60 percent nitrogen and 4.2 percent copper. 
Example XVII 
Copper Salt. Reaction of Cupric Chloride with product of Example IV and 
attachment to alumina. 
The procedure of Example XIII was followed using 20 g alumina instead of 
silica gel. The dried dark brown powder (26.5 g) contained 4.42 percent 
carbon, 0.86 percent nitrogen, and 5.9 percent copper. 
Example XVIII 
Amine Ligand. Reaction of 3-Aminopropyltriethoxysilane with silica gel. 
Into a flask fitted with a stirrer and Dean Stark trap with reflux 
condenser was added 400 g silica gel, 1700 ml toluene, and 120 g (0.54 
mol) 3-aminopropyltriethoxysilane. After heating to reflux for one hour 
100 ml distillate was removed, and the mixture heated an additional two 
hours at reflux. A second 100 ml of distillate was removed, the pot heated 
an additional one hour at reflux and following filtration, the solid was 
washed with toluene (250 ml) and diethyl ether (250 ml). The white filter 
cake was dried at 75.degree. C. under vacuum to yield 459 g of a white 
powder containing 4.91 percent carbon and 1.62 percent nitrogen. 
Example XIX 
Enaminone Ligand-Copper Salt. Reaction of 2,4-Pentanedione with product of 
Example XVI followed by complexation of cupric chloride. 
Into a flask fitted as in Example XVIII was added 300 ml heptane, 40 g of 
Example XVI, and 6.4 g of acetylacetone (2,4-pentanedione). The solution 
was heated to reflux for three hours removing the bottom layer of the 
azeotrope (1.2 ml). After filtering, the solid was washed with heptane (50 
ml) and diethyl ether (100 ml) and dried under vacuum at room temperature 
leaving 42 g of a pale yellow powder containing 10.85 percent carbon and 
1.57 percent nitrogen. Twenty grams of this powder was then charged into a 
flask fitted with a stirrer and addition funnel and 75 ml ethanol added. 
Cupric chloride (4.4 g) was dissolved in 25 ml ethanol and this mixture 
added slowly to the pot at room temperature over 30 minutes. After 
stirring an additional 2 hours the solid was filtered, washed with fresh 
ethanol (50 ml) and dried at room temperature under vacuum affording 22 g 
of a brown powder containing 9.17 percent carbon, 1.43 percent nitrogen 
and 2.6 percent copper. 
Example XX 
Schiff Base Ligand-Copper Salt. Reaction of Salicylaldehyde with Example 
XVI followed by complexation of cupric chloride. 
Same procedure was followed as in Example XIX using 7.8 g salicylaldehyde. 
Initial reaction yielded a bright yellow powder (44 g) containing 12.93 
percent carbon and 1.47 percent nitrogen. Complexation with cupric 
chloride afforded a brown powder (22 g) containing 12.45 percent carbon, 
1.43 percent nitrogen, and 3.3 percent copper. 
Example XXI 
Diamide Ligand-Copper Salt. Attachment of Example II to silica gel followed 
by complexation of cupric chloride. 
Into a flask fitted with a stirrer and Dean Stark trap with reflux 
condenser was added 100 g silica gel, 500 ml toluene, and 30 g of Example 
II. The mixture was heated at reflux a total of four hours removing 25 ml 
of distillate at the end of one and three hours. After filtering, the 
white solid was washed with toluene (100 ml) and diethyl ether (100 ml). 
Drying under vacuum at 75.degree. C. afforded 119 g of a white powder 
containing 7.55 percent carbon and 2.07 percent nitrogen. Into a flask 
containing 100 g of the above solid and 225 ml ethanol was added a 
solution of 20 g cupric chloride in 75 ml ethanol. After stirring at room 
temperature for two hours the mixture was filtered, the solid washed with 
fresh ethanol (100 ml), and dried at room temperature under vacuum to 
yield 110 g of a gold colored powder containing 6.28 percent carbon, 1.89 
percent nitrogen, and 8.2 percent copper. 
CATALYST EVALUATION-DIMETHYL CARBONATE PRODUCTION. 
Example XXII 
Oxidative Carbonylation of Methanol using the copper catalyst from Example 
VII. 
Into a 1 liter Hastelloy autoclave fitted with a glass liner was added 125 
ml methanol and 25 g of the product of Example VII. The reactor was 
flushed with carbon monoxide and pressurized to 1000 psig carbon monoxide 
at room temperature. The mixture was subsequently heated at 100.degree. C. 
for eight (8) hours. After cooling the liquid was analyzed by gas 
chromatography using isooctane as an internal standard and shown to 
contain a 25% yield of dimethyl carbonate based on the copper salt 
charged. 
Example XXIII 
Oxidative Carbonylation of methanol using the copper catalyst from Example 
XI. 
Same procedure as Example XXII using 25 g of the product Example XI. Gas 
chromatographic analyses indicated a 36% yield of dimethyl carbonate. This 
is the best yield obtained. 
Example XXIV 
Oxidative Carbonylation of methanol using the copper catalyst from Example 
XIX. 
Same procedure as Example XXII using 25 g of the product of Example XXI. 
Gas chromatographic analysis indicated an 18% yield of dimethyl carbonate. 
Example XXV 
Oxidative Carbonylation of Methanol using the copper catalyst from Example 
XII. 
Same procedure as Example XXII using 25 g of the product Example XII. Gas 
chromatographic analysis indicated a 25% yield of dimethyl carbonate. 
Example XXVI 
Oxidative Carbonylation of methanol using the copper catalyst from Example 
XIII. 
Same procedure as Example XXII using 25 g of the product of Example XIII. 
Gas chromatographic analysis indicated a 25% yield of dimethyl carbonate. 
Example XXVII 
Oxidative Carbonylation of Methanol using the copper catalyst from Example 
XIV. 
Same procedure as Example XXII using 25 g of the product of Example XIV. 
Gas chromatographic analysis indicated a 24% yield of dimethyl carbonate. 
Example XXVIII 
Oxidative carbonylation of methanol using the copper catalyst from Example 
XV. 
Same procedure as Example XXII using 25 g of the product of Example XV. Gas 
chromatographic analysis indicated a 20% yield of dimethyl carbonate. 
Example XXIX 
Reaction of product of Example II with Silica gel. 
Into a 1 liter 3-neck flask fitted with a mechanical stirrer and Dean-Stark 
trap with reflux condenser was added 100 g silica gel, 400 ml toluene, and 
34 g (0.12 mol) Example II. The mixture was heated at reflux for two hours 
and 50 ml distillate was collected and discarded. After an additional two 
hours at reflux and an additional 50 ml distillate removed the pot was 
cooled to room temperature. After filtering, the resulting white powder 
was Soxhlet extracted with methanol for 24 hours. Subsequent drying at 
50.degree. C. under vacuum afforded 117 g of a white powder containing 
8.54 percent carbon and 2.37 percent nitrogen. 
Example XXX 
Oxidative carbonylation of methanol using cuprous chloride that was 
oxidized in the presence of methanol and the product of Example XXIX. 
Into a 250 ml 3-neck flask fitted with a mechanical stirrer, air inlet 
tube, thermometer, and reflux condenser was added 25 g of the product 
Example XXIX, 5 g (0.05 mol) cuprous chloride and 150 ml methanol. Dry air 
was run through the heterogeneous mixture at 535 ml/min and the pot heated 
at 45.degree. C. for 6 hours. The free flowing green powder containing the 
complexed copper salt was analyzed and found to contain 5.80 percent 
carbon, 1.35 percent nitrogen, and 8.3 percent copper. The resulting 
mixture was charged into a 1 liter Hastelloy autoclave fitted with a glass 
liner. The reactor was flushed with carbon monoxide and pressurized to 
1000 psig carbon monoxide at room temperature. The pot was subsequently 
heated at 100.degree. C. for eight (8) hours. After cooling, the liquid 
was analyzed by gas chromatography using isooctane as an internal standard 
and shown to contain a 69% yield of dimethyl carbonate based on the copper 
salt charge. 
Although this invention has bee illustrated by reference to specific 
embodiments, it will be apparent to those skilled in the art that various 
changes and modifications may be made which clearly fall within the scope 
of this invention.