Reppe chemistry

The principal chemicals based on Reppe chemistry today are propargyl alcohol and butyn-l,4-diol and derivatives such as 2-pyrrohdinone, Ai-vinyl-2-pyrrohdinone, polyvinylpyrroHdinone, vinyl ethers, and tetrahydrofuran (33). 

Reactions of Alkenes and Alkynes in Presence of Metal Carbonyls. Metal carbonyls—e.g., Ni(CO)4, Fe(CO)5, and Co2(CO)s—and hydrocarbonyls— HCO(CO)4 and H2Fe(CO)4—act as catalysts for the transformation of simple unsaturated materials into a wide variety of larger molecules. Perhaps the simplest example is that of hydroformylation (Equation 7). Reppe chemistry... 

The former Reppe chemistry, still practiced in Germany by BASF and in the United States by GAF, also led to new developments as demand for certain intermediates such as the 1,4-butanediol increased. This diol, now also obtained from maleic anhydride, is used to produce PBT polyesters through reaction with terephthalic acid and leads to other major derivates (tetrahydrofuran, butyrolactone, N-vinylpyrrolidone). 

This invention has its roots in Reppe chemistry. In the late 1930s, Reppe in Germany had developed a number of manufacturing processes for bulk chemicals, where acetylene was used as one of the basic building blocks. Even today BASF and Rohm Hass manufacture large quantities of acrylic acid and its esters by hydrocarboxylation of acetylene. This reaction, 4.12, is catalyzed by a mixture of NiBr2 and Cul. It involves high pressure (100 bar) and temperature (220°C), and mechanistically is not fully understood. 

B. Comils, Hydroformylation , A. MuUen, Reppe Chemistry , and A. Mullen, Ring Closure Reactions with CO, in New Syntheses with Carbon Monoxide , ed. J. Falbe, Springer-Verlag, Berhn, 1980. 

Polyvinylpyrrolidone (PVP) is a synthetic polymer derived from the Reppe chemistry and is widely used in the pharmaceutical, personal care, cosmetic, agriculture, beverage, and many industrial applications. PVP is a polar and amorphous polymer which is soluble in water and some organic solvents, such as alcohols, chlorinated hydrocarbons, dimethyl formamide, dimethyl acetamide, and V-methyl pyrrolidone. 

The general acetylene literature up to 1938 is reported on by Nieuwland and Vogt (81). In addition to a translation of Reppe s own work (92), two excellent reviews in the English language of Reppe chemistry are Owens and Johnson (84) and Copenhaver and Bigelow (17). Several other important works on Reppe chemistry are Reppe (93, 94), Hecht and Kroper (44), and Piganiol (86). 

At the end of the 1920 s, Walter Reppe (29, 30, 31, 32) started his experiments on catalytic reactions with acetylene under pressure. On the basis of his studies, which soon were known all over the world as Reppe chemistry, it was possible to construct complicated organic compounds of high value from simple building stones. From the standpoint of the chemical engineer the greatness of his achievement was that the... 

In continuation of Reppe chemistry, catalytic reactions of acetylene with carbon monoxide and compounds containing hydrogen atoms, e.g. water or alcohol, were developed in the process of carbonylation (31), as seen in Equations 3 and 4. 

In the same way as in Reppe chemistry the reaction conditions could be mitigated by including organic bases in the catalysts, more and more organic molecules will be added as ligands to central metal atoms. Thus catalysts will be built up according to the pattern of such biocatalysts as chlorophyll and porphyrine which are effective even at mild conditions. 

Commercial petrochemical processes using syngas or carbon monoxide are based on four principal classes of reactions phosgenation, Reppe chemistry, hydroformylations, and Koch carbonylations. Phosgenation is a key step in the manufacture of polyurethanes, polycarbonates, and monoisocyanates. Reppe chemistry is the basis for acetic acid and acetic anhydride production as well as formic acid and methyl methacrylate synthesis. Hydroformylations utilize syngas in the oxo synthesis to make a wide variety of aldehydes and long-chain alcohols. The fourth class of reactions are Koch carbonylations. Koch carbonylations are used commercially to produce neo acids which are specialty products that serve markets similar to 0X0 alcohols. 

Brayton or Joule, 16 Claude, 12, 16-18 expander, 14-5 Heylandt, 17, 18,21,22 pumped LOX, 23, 24 Regenerators, 8 Reppe chemistry ... 

Contrary to the impression given by some histories of the chemical industry, Reppe chemistry was still largely embryonic in 1943, with the partial exception of the vinyl ethers. Most of the new Reppe reactions were still at the laboratory, or at best at the pilot plant, stage. In fact, Reppe chemistry was responsible for less than 2Vz per cent of... 

Similar reactions are possible with acetylenic and alcoholic substrates, but the former (an industrial component of Reppe chemistry which held sway for a number of years) are no longer of any practical importance. These specific types of carbonylation are referred to as hydroxycarboxylation. We shall very briefly consider some important reactions belonging to these classes. 

Butanediol is the main intermediate to tetrahydrofuran and y-butyro-lactone, but is finding increasing use in the production of polybutylene terephthalate, an engineering plastic. Production in the U.S.A. (over 200 kt per annum) and Europe (approx. lOOkt per annum) is mainly via Reppe chemistry, based on acetylene ... 

The favorable effects of phosphine ligands in catalysis have been known for more than half a century. One of the first reports involves the use of triphenylphosphine in the Reppe chemistry, the reactions of alkynes, alcohols and carbon monoxide to make acryhc esters [2]. An early example of a phosphine-modified catalytic process is the Shell process for alkene hydroformylation nsing a cobalt catalyst containing an alkylphoshine [3]. 

Details high pressure reactions catalyzed by heavy metal acetylldes, especially copper acetyllde, or metal carbonyls are called Reppe Chemistry, which Is behind synthesis of PVP ... 

The shift from coal to oil, of course, had major consequences for the chemical industry. Alkenes, instead of synthesis gas and acetylene, became the basic building blocks. Homogeneous catalysis became increasingly important for the production of chemicals. We already mentioned the Reppe chemistry, based on acetylene as the main feedstock. In 1938, the same year that Reppe started his work, another German scientist, Otto Roelen, discovered the reaction of olefins with carbon monoxide and hydrogen over a cobalt carbonyl catalyst to form aldehydes, known... 

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