Untersuchungen über die Bildung von Nitrilen

Kurtz, Peter

doi:10.1002/jlac.19515720103

Cited by 37 publications

(4 citation statements)

References 81 publications

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“…Considering evaporites, and cyanocuprates in the context of the foregoing, we were drawn to literature concerning the cross-coupling of hydrogen cyanide 11 and acetylene 32 to acrylonitrile 33 28 using copper(I) salts solubilised in water by high concentrations of sodium or potassium chloride, a system known as the Nieuwland catalyst. This combination of reagents and salts appeared prebiotically plausible according to our developing geochemical scenario, and we thus concluded that copper-catalysed cross-couplings could have occurred on the early Earth.…”

Section: Resultsmentioning

confidence: 99%

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

et al. 2015

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A minimal cell can be thought of as comprising informational, compartment-forming and metabolic subsystems. Imagining the abiotic assembly of such an overall system, however, places great demands on hypothetical prebiotic chemistry. The perceived differences and incompatibilities between these subsystems have led to the widely held assumption that one or other subsystem must have preceded the others. Here, we have experimentally investigated the validity of this assumption by examining the assembly of various biomolecular building blocks from prebiotically plausible intermediates and one-carbon feedstock molecules. We show that precursors of ribonucleotides, amino acids and lipids can all be derived by reductive homologation of hydrogen cyanide and some of its derivatives and thus that all the cellular subsystems could have arisen simultaneously through common chemistry. The key reaction steps are driven by UV light, use hydrogen sulfide as reductant and can be accelerated by Cu(I)-Cu(II) photoredox cycling.Viewing the cell as an ensemble of subsystems 1 begs the question 'did the subsystems emerge together, or one after the other at the origin of life?' The consensus that sequential emergence is more likely 2 (though with opinions differing as to which subsystem came first [3][4][5] ) has been based on the notion that different, mutually incompatible chemistries are needed to make the various subsystems. We set out to explore this experimentally by evaluating the assembly chemistry of the various subsystems. Investigation of the assembly chemistry of an informational subsystem based on RNA led to our discovery of an efficient synthesis of activated pyrimidine ribonucleotides 6 . In this synthesis (Fig. 1a, bold, blue arrows), the C 2 sugar glycolaldehyde 1 undergoes phosphate-catalysed condensation with cyanamide 2 to give 2-aminooxazole 3. This heterocycle then participates in a C-C bond Reprints and permissions information is available online at www.nature.com/reprints. Additional informationSupplementary information and chemical compound information are available in the online version of the paper. Competing financial interestsThe authors declare no competing interests. forming reaction with the C 3 sugar glyceraldehyde 4 giving rise to a mixture of pentose aminooxazolines. Reaction of the arabino-configured aminooxazoline 5 with cyanoacetylene 6 then furnishes an anhydronucleoside 7 which on heating with phosphate in urea 8 -a by-product of the first step of the sequence -is transformed into ribo-cytidine-2′, 3′-cyclic phosphate 9. UV irradiation then partially converts this nucleotide into uridine-2′, 3′-cyclic phosphate 10 and destroys stereoisomeric impurities. Europe PMC Funders GroupWe subsequently showed that the C 2 and C 3 sugars, 1 and 4, can be sequentially provided by a Kiliani-Fischer-type homologation of hydrogen cyanide 11 using Cu(I)-Cu(II) photoredox chemistry (Fig. 1a, bold, green arrows) 8,9 . Using hydrogen sulfide 12 as the stoichiometric reductant -in which case the inclusion o...

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Section: Resultsmentioning

confidence: 99%

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

et al. 2015

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“…All these compounds may be converted to the appropriate saturated alkylated dicarboxylic acids by standard methods. The addition of hydrogen cyanide to unsaturated esters and nitriles and other unsaturated compounds has been discussed, and the literature has been surveyed in two review articles (405,493) and a monograph (466).…”

Section: (D) Reactions With Unsaturated Compoundsmentioning

confidence: 99%

Syntheses Of Alkylated Alkanedioic Acids

Diaper¹,

KUKSIS²

1959

Chem. Rev.

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example of such a synthesis is the conversion of 2-pentenal, through a Reformatsky condensation with ethyl -bromopropionate and oxalation of the unsaturated product, eventually to 2,6-dimethylsuberic acid (401).It has been shown that formates and oxalates may function as carbonyl components in a Reformatsky synthesis. Ethyl -bromoisobutyrate reacts with ethyl oxalate (569) and with ethyl formate (82), giving hydroxy esters which could be converted to 2,2-dimethylsuccinic and 2,2,4,4-tetramethyIglutaric acids, respectively.The application of the Reformatsky reaction to nitriles (154) leads to the formation of ketones in a manner comparable with the Grignard reaction and is a convenient method for the synthesis of /3-keto esters.By varying the nature of the carbonyl compounds and the halo esters employed, many alkylated dicarboxylic acids have been prepared with the help of this reaction, yet the possible products may be of only a few types. Branching is confined to the a-and ß-positions at one or both ends of the chain, and while the -position may bear one, two, or no alkyl groups, the /3-position cannot bear more than one side chain.Theoretically, in all of the above cases the ester groups of the final products may be converted into aldehyde or keto groups through the acyl chlorides and dialkyl metals (142).A repetition of the Reformatsky process would lengthen the chain with or without further branching at the new points of junction of carbon chains (629).

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“…Less reactive addenda such as benzyl cyanide, desoxybenzoin, acetophenone, cyclopentadiene (17), ammonia, and aniline (67) do not form stable adducts. There is indirect evidence for the formation of an unstable 1,6adduct with ammonia (48). Reduction of a mixture of ammonia and 2,4-pentadienenitrile with hydrogen and Raney nickel produced 5-aminopentanenitrile and pentamethylenediamine in low yield.…”

Section: Introductionmentioning

confidence: 99%

Unsymmetrical 1,6-Additions To Conjugated Systems

Ralls¹

1959

Chem. Rev.

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Untersuchungen über die Bildung von Nitrilen

Cited by 37 publications

References 81 publications

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism

Syntheses Of Alkylated Alkanedioic Acids

Unsymmetrical 1,6-Additions To Conjugated Systems

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