Acrylic acid Catalyst preparation

Early catalysts for acrolein synthesis were based on cuprous oxide and other heavy metal oxides deposited on inert silica or alumina supports (39). Later, catalysts more selective for the oxidation of propylene to acrolein and acrolein to acrylic acid were prepared from bismuth, cobalt, iron, nickel, tin salts, and molybdic, molybdic phosphoric, and molybdic silicic acids. Preferred second-stage catatysts generally7 are complex oxides containing molybdenum and vanadium. Other components, such as tungsten, copper, tellurium, and arsenic oxides, have been incorporated to increase low temperature activity7 and productivity7 (39,45,46). 

At the beginning of the synthesis, a cis-sUyl-substituted acrylic acid is prepared from the corresponding alkynoic acid by reduction with a Lindlar catalyst, then activated with oxalyl chloride and reacted with Koga s auxiliary. 

Asymmetric hydrogenation has been achieved with dissolved Wilkinson type catalysts (A. J. Birch, 1976 D. Valentine, Jr., 1978 H.B. Kagan, 1978). The (R)- and (S)-[l,l -binaph-thalene]-2,2 -diylblsCdiphenylphosphine] (= binap ) complexes of ruthenium (A. Miyashita, 1980) and rhodium (A. Miyashita, 1984 R. Noyori, 1987) have been prepared as pure atrop-isomers and used for the stereoselective Noyori hydrogenation of a-(acylamino) acrylic acids and, more significantly, -keto carboxylic esters. In the latter reaction enantiomeric excesses of more than 99% are often achieved (see also M. Nakatsuka, 1990, p. 5586). 

Specifically MSA has been found to be more effective than -toluenesulfonic acid and sulfuric acid in preparing dioctyl phthalate (405). A U.S. patent also discloses its use to prepare light-colored fatty esters (406). It is also important as a catalyst to prepare acrylates, methacrylates, adipates, phthalates, trimeUitates, thioglycolates, and other esters. 

Acrylic Esters. A procedure has been described for preparation of higher esters from methyl acrylate that illustrates the use of an acid catalyst together with the removal of one of the products by azeotropic distillation (112). Another procedure for the preparation of butyl acrylate, secondary alkyl acrylates, and hydroxyalkyl acrylates using -toluenesulfonic acid as a catalyst has been described (113). Alurninumisopropoxide catalyzes the reaction of amino alcohols with methyl acrylate and methyl methacrylate. A review of the synthesis of acryhc esters by transesterification is given in Reference 114 (see... 

The main use of acrolein is to produce acrylic acid and its esters. Acrolein is also an intermediate in the synthesis of pharmaceuticals and herhicides. It may also he used to produce glycerol hy reaction with isopropanol (discussed later in this chapter). 2-Hexanedial, which could he a precursor for adipic acid and hexamethylene-diamine, may he prepared from acrolein Tail to tail dimenization of acrolein using ruthenium catalyst produces trans-2-hexanedial. The trimer, trans-6-hydroxy-5-formyl-2,7-octadienal is coproduced. Acrolein, may also he a precursor for 1,3-propanediol. Hydrolysis of acrolein produces 3-hydroxypropionalde-hyde which could he hydrogenated to 1,3-propanediol. ... 

Enantioselective Diels-Alder reactions proceed smoothly in the presence of a chiral Sc catalyst, prepared in situ from Sc(OTf)3, R)- I )-l,l -bi-2-napluhol [(R)-BINOL], and a tertiary amine in dichloromethane.58 The catalyst is also effective in Diels-Alder reactions of an acrylic acid derivative with dienes (Scheme 14). 

The addition of dopants is found to have beneficial effects. However, they are not restricted only to transition metals. The hydrogenation of acrylic acid can be promoted significantly by the addition of neodymium ions onto the palladium particles [142], The selective transformation of 3,4-dichloronitrobenzene to the corresponding aniline has been selected to test pre-prepared Pt hydrosols as heterogeneous catalyst precursors (see Figure 3.9) [143],... 

A possible economically attractive alternative would be the production of acrylic acid in a single step process starting from the cheaper base material propane. In the nineteen nineties the Mitsubishi Chemical cooperation published a MoVTeNb-oxide, which could directly oxidise propane to acrylic acid in one step [6], Own preparations of this material yielded a highly crystalline substance. Careful analysis of single crystal electron diffraction patterns revealed that the MoVTeNb-oxide consists of two crystalline phases- a hexagonal so called K-Phase and an orthorhombic I-phase, which is the actual active catalyst phase, as could be shown by preparing the pure phases and testing them separately. 

The phosphinated ligands 135 and 136 prepared from poly(acrylic acid) and from poly(ethyleneimine), respectively, gave active hydroformylation catalysts in reaction with [Rh(acac)(CO)2]. Under the conditions of Table 4.6 low conversions were observed in aqueous/organic biphasic systems, due to the low solubility of 1-octene. Addition of a surfactant (SDS) or an organic co-solvent (MeOH) led to dramatic increases in the yield of aldehydes, revealing the high intrinsic activity of the catalyst [120]. 

BINAP core-functionalized dendrimers were synthesized by Fan et al. (36), via condensation of Frechet s polybenzyl ether dendritic wedges to 5,5 -diamino-BINAP (26—28). The various generations of BINAP core-functionalized dendrimers were tested in the ruthenium-catalyzed asymmetric hydrogenation of 2-[p-(2-methyl-propyl)phenyl]acrylic acid in the presence of 80 bar H2 pressure and in a 1 1 (v/v) methanol/toluene mixture. As later generations of the in situ prepared cymeneruthe-nium chloride dendritic catalysts were used, higher activities were observed (TOF values were 6.5, 8.3, and 214 h respectively). Relative to those of the BINAP... 

The 7-lactones described below can be prepared in good yield in a one-step process by radical addition of primary fatty alcohols to acrylic acid, using di-tert-butyl peroxide as a catalyst. A patent claims a high yield when the reaction is carried out in the presence of alkali phosphates or alkali sulfates [196]. 

Claisen orthoester rearrangement.2 This reagent can be used to prepare methyl a-substituted acrylates from allylic alcohols. 2,4,6-Trimethylbcnzoic acid is used as the acid catalyst.1... 

During the history of a half century from the first discovery of the reaction (/) and 35 years after the industrialization (2-4), these catalytic reactions, so-called allylic oxidations of lower olefins (Table I), have been improved year by year. Drastic changes have been introduced to the catalyst composition and preparation as well as to the reaction process. As a result, the total yield of acrylic acid from propylene reaches more than 90% under industrial conditions and the single pass yield of acrylonitrile also exceeds 80% in the commercial plants. The practical catalysts employed in the commercial plants consist of complicated multicomponent metal oxide systems including bismuth molybdate or iron antimonate as the main component. These modern catalyst systems show much higher activity and selectivity... 

The reaction of a-oxo acids with nitriles in the presence of an add catalyst gives acylamino acrylic acid derivatives, which are then used to prepare a.P-didehydropeptidesJ85 861 The reaction proceeds with a high degree of purity and is less time consuming. The reaction takes place initially to give the imino chloride 26, which subsequently reacts with the enolic form of the oxo acid. Several a-haloacyl-DHAs 27 have been prepared (Scheme 9) from which the corresponding a-aminoacyl-DHA can be prepared by ammonolysis in aqueous ammonia. 

The oxidation of propane into acrylic acid in the presence of heteropoly catalysts prepared from H3PM012O40 and antimony pentachloride gave rather low conversion and selectivity [10 and 19%, respectively (2% yield)] (352). Recently, a yield of ca. 9% was obtained with H5PV2M010O40 (353). The addition of Cr ion also enhanced the catalytic performance (354). 

With Tartrate-Derived Chiral 1,4-Diol/Ti Complexes A catalytic asymmetric Diels-Alder reaction is promoted by the use of a chiral titanium catalyst prepared in situ from (Pr O TiC and a tartrate-derived (2.R,3.R)-l,l>4,4-tetraphenyl-2,3-0-(l-phenylethylidene)-l,2,3,4-butanetetrol. This chiral titanium catalyst, developed by Narasaka, has been successfully executed with oxazolidinone derivatives of 3-borylpropenoic acids as P-hydroxy acrylic acid equivalents [40] (Eq. 8A.21). The resulting chiral adduct can be utilized for the first asymmetric total synthesis of a highly oxygenated sesquiterpene, (-i-)-Paniculide. 

Asymmetric Diels-AUer reactions The observation that simple acyloxy-boranes such as H2BOCOCH=CH2, prepared by reaction of BH3 with acrylic acid, can serve as Lewis acid catalysts for reactions of the a,P-unsaturated acids with cyclopentadiene (15, 2) has been extended to the preparation of chiral acyloxy-boranes derived from tartaric acid. The complex formulated as 3, prepared by reaction of BH3 with the monoacylated tartaric acid 2, catalyzes asymmetric Diels-Alder reactions of a,P-enals with cyclopentadiene with high enantioselectivity. The process is applicable to various dienes and aldehydes with enantioselectivities generally of 80-97 % ee. 

Acrylic acid (CH2=CHC02H, melting point 13.5°C, boiling point 141°C, density 1.045, flash point 68°C) and acrylates were once prepared by reaction of acetylene and carbon monoxide with water or an alcohol, with nickel carbonyl as catalyst. 

Acyloxyboranes. Yamamoto et a/.1 have used the known reactivity of borane with carboxylic acids to activate acrylic acids for Diels-Alder reactions. Thus addition of BH3-THF to acrylic acids at 0° furnishes an acyloxyborane formulated as 1, which undergoes cycloaddition (equations I and II). The reaction proceeds satisfactorily even when borane is used in catalytic amounts. A chiral acyloxyborane, BL, prepared from a tartaric acid derivative, can serve as a catalyst for an asymmetric Diels-Alder reaction (equation III). 

Lin MM. Complex metal-oxide catalysts for selective oxidation of propane and derivatives. I. Catalysts preparation and application in propane selective oxidation to acrylic acid. Applied Catalysis, A General. 2003 250(2) 305-318. 

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