Aug. 11, 2005  3  US  2005/0176978 Al  lower (alkyl)ester of a fatty acid comprising combining the  fatty acid, a lower alkanol and a catalyst of formula I or II  under conditions wherein the catalyst catalyzes the forma› tion of the corresponding lower (alkyl)ester. In a preferred  embodiment, the fatty acid is present in an organic or  synthetic feedstock such as an animal or vegetable oil that  comprises a major portion of glycerol fatty acid esters, such  as the mono-, di- and/or tri-esters.  [0018]  Preferably the fatty acid portion of the ester or  glyceride is derived from a (C$_{8}$-C$_{22}$ ) fatty acid, preferably a  (C$_{10}$-C$_{18}$ ) fatty acid, which is a saturated alkyl ester that  optionally comprises 1-3 CH=CH moieties in the alkyl  chain. The (C$_{1}$ -C$_{3}$ )  alcohols are preferably methanol, etha› nol, propanol or i-propyl alcohol, although higher alkanols  such as (C$_{4}$ -C$_{6}$ )  alkanols may be useful in some applications.  The alcohol is preferably used in a molar excess over the  starting material acid and/or ester component of the feed› stock, since such esterification/transesterification reactions  are highly reversible.  [0019]  FIG. 1  depicts general synthetic routes to precur› sors compounds of formula I, (3, and 7), and 5.  [0020]  FIG. 2  depicts synthetic routes to specific precur› sor compounds of formula I, 11 and 13 and 12.  [0021]  FIG. 3  depicts synthetic routes to specific precur› sors of compounds of formula I and II (15 and 17).  [0022]  FIG. 4  depicts a synthetic route to a precursor  compound of a compound of formula I (20a) and salt (21a).  [0023]  FIG. 5  depicts intermediates useful in the present  invention.  [0024]  FIG. 6  is a graph depicting the transesterification  of soybean oil to methyl soyate in methanol at 25°  C. with  mesoporous silica supported superbases.  [0025]  Mesoporous Silicates  [0026]  Mesoporous silicates useful in the present method  typically have a particle size of about 50 nm to about 1  µm.  In one embodiment, the mesoporous silicates have a particle  size of at least about 100 nm, or preferably at least about 200  nm. However, particle size is not critical to the practice of  the invention and particulate bodies of larger size can be  used in some cases, e.g., to facilitate separations. In another  embodiment, the mesoporous silicates have a particle size of  less than about 750 nm.  As  conventionally prepared, they are  spherical, but they have also been prepared under conditions  that yield other shapes such as rods. The articles of the  invention can include mesoporous silicates of any shape,  provided the pore structure is suitable for receiving the  feedstock, e.g., is uniform and of an appropriate diameter.  [0027]  The mesoporous silicate pores typically have a  diameter of from about 1-100 nm. In one embodiment of the  invention, the pores have a diameter of at least about 2 nm.  In other embodiments, the pores have diameters of greater  than about 5 nm, or greater than about 10 nm. Typically, the  pores have a diameter of less than about 75 nm or less than  about 50 nm.  [0028]  The mesoporous silicate can be prepared from  surfactant micelles of C$_{10}$-C$_{16 }$ alkyl(trialkyl)ammonium  salts in water, followed by introduction into the solution of  an  alkyl  orthosilicate,  such  as  tetraethylorthosilicate  (TEOS),  and one or more functionalized silanes, such as one  or more mercaptoalkyl-, chloroalkyl-, aminoalkyl-, carboxy› alkyl-, sulfonylalkyl-, arylalkyl-, alkynyl-, or alkenyl-si› lanes, wherein the (C$_{2}$-C$_{10}$)alkyl chain is optionally inter› rupted by -S-S, amido(-C( =O)NR-),  -0-,  ester(› C(=O)O-), and the like. The aqueous mixture is stirred at  moderate temperatures until the silicate precipitates, after  which it is collected and dried. The surfactant "template" is  then removed from the pores of the ordered silicate matrix,  for example, by refluxing the silicate in aqueous-alcoholic  HCl. The remaining solvent can be removed from the pores  of the silicate by placing it under high vacuum. The func› tional groups incorporated onto the surface of the pores can  be quantified and used as linker moieties to bind to the  functionalized super base, or they can be further modified by  attaching terminally-functionalized organic linker moieties  that can be reacted with functional groups on Z. The polarity  of the interior of the pores can also be adjusted by adding  other functionalized silanes to the reaction mixture, includ› ing ones comprising non-polar inert groups such as aryl,  perfluoroalkyl, alkyl, arylakyl and the like. The exterior of  the silicate matrix can also be functionalized by grafting  organic moieties comprising functional groups thereto.  These groups can in turn be employed to link the particles  to catalytic moieties such as functionalized "superbase"  catalysts.  [0029]  Superbase-Functionalized Mesoporous Solid Cata› lysts  [0030]  The three commercially available "superbases" of  type 1, (la-le in  FIG. 5)  are exceptionally strong nonionic  bases with pKa’s of ca. 32 in acetonitrile and have superior  catalytic activities for a wide variety of reactions including  transesterification. See, e.g., U.S. Pat. No. 5,051,533. Their  derivatives of type 2a-c are weaker but still very strong bases  and catalysts and both types of homogeneous catalysts  convert vegetable oils, including soybean oil, to their methyl  esters at room temperature. These catalysts deprotonate  alcohols to liberate alkoxide ion ( the active species in the  catalyst system) in concentrations effective for transesteri› fication.  [0031]  Compounds of types 1 and 2 lend themselves well  to chemically bonding to mesoporous silica surfaces via  trialkoxysilyl groups (see 11, 15 and 17). The Si(OMe  h  group linker reacts with up to three Si OH groups in the silica  to eliminate MeOH giving robust SiOSi anchors. Precursors  11, 15 and 17 per se homogeneously and efficiently catalyze  soybean oil transesterification to soy methyl ester (i.e.,  100% conversion of 200 mL of soybean oil in 400 mL of  methanol in 24 to 36 h at room temperature using only 0.25  mmol of catalyst). These catalysts are greatly superior to  commercially available amine-type nonionic bases or their  polymer-mounted forms.  [0032]  Intermediates 20a, Sc and 6b, have also been  prepared, which are designed to take advantage of the vinyl  group for linkage to mesoporous solid supports which  comprise  a  mercaptoalkyl  functional  group  already  covalently bound thereto. The mercaptoalkyl groups react  with vinyl groups to give strong CSC linkages. Such cata- DETAILED DESCRIPTION OF THE  INVENTION  BRIEF DESCRIPTION OF THE DRAWINGS 