Acrolein hydroformylation

Ca.ta.lysts, A small amount of quinoline promotes the formation of rigid foams (qv) from diols and unsaturated dicarboxyhc acids (100). Acrolein and methacrolein 1,4-addition polymerisation is catalysed by lithium complexes of quinoline (101). Organic bases, including quinoline, promote the dehydrogenation of unbranched alkanes to unbranched alkenes using platinum on sodium mordenite (102). The peracetic acid epoxidation of a wide range of alkenes is catalysed by 8-hydroxyquinoline (103). Hydroformylation catalysts have been improved using 2-quinolone [59-31-4] (104) (see Catalysis). 

The simplest a,/3-unsaturated aldehyde, acrolein, gives nearly quantitative yields of the hydrogenation product propionaldehyde under hydroformylation conditions. Most of the research has been conducted on acetal or acetate derivatives. 

Maeda and Yoshida (74) found that acrolein cyclic acetals (17-19) could be hydroformylated with cobalt carbonyl catalyst in benzene at 110°C and 200 atm of hydrogen and carbon monoxide. 

The cobalt-catalyzed hydroformylation of acrolein diacetate in ethanol proceeded in a complicated fashion. The products obtained are listed in Table XXVI. These products are rationalized by the following sequence The initial products formed were m-aldehyde (l,l-diacetoxy-3-formylpro-pane, ca. 60%), isoaldehyde (1,1 -diacetoxy-2-formylpropane, 5-10%) and propionaldehyde diacetate, ca. 5%. In the alcohol solvent, the aldehydes were converted to the corresponding acetals. A portion of the n-aldehyde was converted to 2,5-diethoxytetrahydrofuran by acid catalysis, and the isoaldehyde was thermally decomposed to 2-methyl-3-acetoxyacrolein. 

Finally, cobalt hydroformylation of acrolein diacetate in ethanol, in the presence of excess ethyl orthoformate, simplified the reaction and resulted in high yields of l,l-diacetoxy-4,4-diethoxybutane (n-isomer), lower yields of l,l-diacetoxy-2-methyl-3,3-diethoxypropane (iso). The favorable effects of ethyl orthoformate are shown in Table XXVII. 

The hydroformylation of acrolein cyclic acetals has received considerable attention in the recent patent literature as a route to 1,4-butanediol (76-52). This diol is a comonomer for the production of polybutylene terephthalate, an engineering thermoplastic. The standard method for its manufacture has been from acetylene and formaldehyde, as shown in Eqs. (37) and (38) ... 

Hydroformylation of Acrolein Diacetate in the Presence of Ethyl Orthoformate (74)... 

Acrolein is manufactured from low-cost propylene, and its hydroformyl-ation to 1,4-butanediol or a precursor of it could provide a more economical route. 

The regiochemistry of hydroformylation of acrolein cyclic acetals can be controlled to some extent by the presence or absence of phosphine. Excess phosphine provides predominately the straight chain aide-... 

Functionalization of hydrocarbons from petroleum sources is mainly concerned with the introduction of oxygen into the hydrocarbon molecule. In general, two ways are open to achieve oxygen functionalization oxidation and carbonylation. Oxidation is commonly encountered in the synthesis of aromatic acids, acrolein, maleic anhydride, ethene oxide, propene oxide, and acetaldehyde. Hydroformylation (CO/H2) (older literature and the technical literature refer to the oxo reaction) is employed for the large-scale preparation of butanol, 2-ethylhexanol, and detergent alcohols. The main use of 2-ethylhexanol is in phthalate esters which are softeners in PVC. The catalysts applied are based on cobalt and rhodium. (For a general review see ref. 3.)... 

Scheme 1 Methods for the synthesis of aldehyde functional polysiloxanes described in the literature [1-5] (1) hydroformylation, (2) and (3) ozonolysis, (4) hydrosilylation of acrolein acetals and acid hydrolysis...

Previously, PTT was produced based on 1,3-PD by chemical synthesis. The traditional chemical routes of commercial synthesis for 1,3-PD production are from acrolein by DuPont and from ethylene oxide by Shell. The route of DuPont is that acrolein is converted to 3-hydroxypropionaldehyde (3-HPA) by hydration, followed to produce 1,3-PD by hydrogenation (Lawrence and Sullivan, 1972). Shell followed the method of hydroformylation of ethylene oxide to 3-hydroxypropanal. This is subsequently extracted and hydrogenated for the production of 1,3-PD (Sullivan, 1993). 

Acrolein acetals 15 bearing an alkyl or aryl substituent in the 2-position are regiospecifically hydroformylated to the corresponding succinaldehyde monoacetals 16 with rhodium catalysts (Figure 6) [21],... 

Figure 6. Hydroformylation of acrolein dimethylacetal. Synthesis of partially protected 1,4-...

Acetals of acrolein react depending on the hydroformylation conditions to form methylmalonaldehyde or succinaldehyde monoacetals (Scheme 4.46) [92, 93]. Reactions have been conducted in 100 g to several kilogram scales. Cleavage of the acetal and final reduction with Raney-Co produces isomeric butanediols. 

The 6 4 mixture of endo- and exo-bicycloheptenealdehyde [263], obtained from the Diels-Alder reaction [262] of acrolein with cyclopenta-diene, was hydroformylated with rhodium catalyst [254]. 

Most unsaturated esters are hydroformylated in good yield (table 18). The conjugation in a,p-unsaturated esters is weaker than in unsaturated aldehydes (the resonance energy of crotonaldehyde, for example, is 2.4 Kcal/mole higher than for ethyl crotonate [7]). Thus, conjugated unsaturated esters such as acrylates and crotonates, in contrast to acrolein and crotonaldehyde, can be converted to aldehyde products with synthesis gas. 

Conjugated and unconjugated unsaturated nitriles are both susceptible to hydroformylation. Few examples are found in the literature and most of the work has been with acrylonitrile (table 21). The aldehyde group is incorporated mainly in the -position, but the reaction is strongly solvent dependent and byproducts are frequently produced, mainly propionitrile, acrolein, propyl amine and ammonia (see also ref. [972, 973] and [985]). 

Acetylenes are much less adapted to hydroformylation than olefins. Very few examples are reported in the literature. Roelen reported [23] that acetylene reacted with synthesis gas in the presence of cobalt even at low pressure (10 atm, 140-150 °C) the primary reaction was the formation of acrolein. 

The hydroformylation of ethylene oxide gives acrolein in very low yields, which is not surprising in view of its extraordinary reactivity in the main, resinous products are obtained. The reactions of ethylene oxide, propylene oxide, cyclohexene oxide, styrene oxide and epichlorhydrin were studied by Takegami et al. [297] at normal conditions. They found that generally internal and conjugated olefin oxides were more reactive than terminal ones and established the following order of reactivity cyclohexene oxide (appr. 5) > styrene oxide > propylene oxide (1) > ethylene oxide epichlorhydrin (1/20-1/10) (the numbers give the relative reactivity). 

Maeda and Yoshida 238, 239) by hydroformylation of acrolein obtained l,l-diacetoxy-4,4-dialkoxybutane (17), which by Buecherer s reaction gave (3-(hydanto-5-yl-)propionaldehyde acetal (18). The phenyl-hydrazone of (18), by the Fischer indole synthesis, gave tryptophan hydantoin (20). Attempts to obtain crystalline (20) were unsuccessful,... 

Maeda, L, and R. Yoshida The Reaction Products of the Hydroformylation of Acrolein Acetals and Acetates. Bull. Chem. Soc. Japan 41, 2969-2974 (1968). 

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