Kobalt‐katalysiert Cycloadditionen von Alkinen und Nitrilen zu Pyridinen: Ein neuer Zugang zu Pyridoxin (Vitamin B<sub>6</sub>)

Geiger, R.; Lalonde, Michel; Stoller, Hansijörg; Schleich, K.

doi:10.1002/hlca.19840670513

Cited by 65 publications

(14 citation statements)

References 9 publications

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“…A different approach to the synthesis of pyridine derivatives by employing a cobalt-catalyzed [2+2+2] cycloaddition was established by Parnell and Vollhard [123] as well as by Geiger et al (Scheme 22). [124] Acetonitrile and a,w-diynes could be transformed into pyridoxine. However, the selectivity of this reaction was moderate due to competitive formation of carbocycles.…”

Section: Methodsmentioning

confidence: 99%

One Hundred Years of Vitamins—A Success Story of the Natural Sciences

Eggersdorfer¹,

Laudert²,

Létinois³

et al. 2012

Angew Chem Int Ed

257

209

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The discovery of vitamins as essential factors in the diet was a scientific breakthrough that changed the world. Diseases such as scurvy, rickets, beriberi, and pellagra were recognized to be curable with an adequate diet. These diseases had been prevalent for thousands of years and had a dramatic impact on societies as well as on economic development. This Review highlights the key achievements in the development of industrial processes for the manufacture of eight of the 13 vitamins.

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Section: Methodsmentioning

confidence: 99%

One Hundred Years of Vitamins—A Success Story of the Natural Sciences

Eggersdorfer¹,

Laudert²,

Létinois³

et al. 2012

Angew Chem Int Ed

257

209

View full text Add to dashboard Cite

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“…50 This methodology was applied in the total synthesis of vitamin B 6 . 51,52 In 1983, they succeeded in applying Z 5 -cyclopentadienyldicarbonylcobalt in the cyclization of 1,2-bis(propargyl)-1,2,3,4-tetrahydroisoquinolines with alkynes. 53 This procedure provides a novel synthetic entry into various tetrahydroprotoberberine nuclei.…”

Section: Six-membered and Other Heterocyclesmentioning

confidence: 99%

CHAPTER 5. Cobalt-Catalyzed Heterocycle Synthesis

2014

Catalysis Series

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Cobalt has the chemical configuration [Ar]4s 2 3d 7 and has oxidation states Co(II) and Co(III). Cobalt has many applications in a wide range of areas. In materials, cobalt is primarily used as the metal, for example, in the preparation of magnetic, wear-resistant and high-strength alloys. In biology, cobalt is the active center of coenzymes called cobalamins, the most common example of which is vitamin B 12 . As such, it is an essential trace dietary mineral for all animals. Cobalt in inorganic form is also an active nutrient for bacteria, algae and fungi. In chemistry, various cobalt compounds are used as oxidation catalysts in chemical reactions. Cobalt acetate is used for the conversion of xylene to terephthalic acid, the precursor to the bulk polymer poly(ethylene terephthalate). Typical catalysts are the cobalt carboxylates (known as cobalt soaps). They are also used in paints, varnishes and inks as 'drying agents' through the oxidation of drying oils. The same carboxylates are also used to improve the adhesion of steel to rubber in steel-belted radial tires. Cobalt-based catalysts are also important in reactions involving carbon monoxide. In this chapter, the applications of cobalt catalysts in the synthesis of heterocycles is discussed. Five-Membered HeterocyclesIn 1986, Pattenden and co-workers reported a cobalt-promoted oxidative freeradical cyclization of alkyl bromides, 1 by which functionalized butyrolactones were selectively formed in good yields. In 1990, a convenient method for the stereoselective preparation of trans-2-hydroxymethyltetrahydrofurans by the oxidative cyclization of 5-hydroxy-1-alkenes was developed by Inoki and Mukaiyama. 2 They used bis(1-morpholinocarbamoyl-4,4-dimethyl-1,3-pentanedionato)cobalt(II) [Co(modp) 2 ] as the catalyst with molecular oxygen as the RSC Catalysis Series No.

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“…A different approach to the synthesis of pyridine derivatives by employing a cobalt‐catalyzed [2+2+2] cycloaddition was established by Parnell and Vollhard123 as well as by Geiger et al. (Scheme ) 124. Acetonitrile and α,ω‐diynes could be transformed into pyridoxine.…”

Section: Pyridoxine (Vitamin B6)mentioning

confidence: 99%