Flashback: 50 Years Ago
Angewandte Chemie International Edition was first published in 1962, the mother journal first in 1888. In this monthly flashback, we feature some of the articles that appeared 50 years ago. This look back can open our eyes, stimulate discussion, or even raise a smile.
Archive: 2013 2012
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2014, 53, No. 13, 3298
Unsaturated fatty acids was the topic of a Review by L. D. Bergelson and M. M. Shemyakin, who described how carbonyl olefination reactions can be sterically controlled to produce either cis or trans olefins. The topic of saturated and unsaturated fatty acids, in particular trans fatty acids, is still very much in the foreground today (for a recent Essay see Angew. Chem. Int. Ed. 2013, 52, 5220).
M. Schlosser (see Angew. Chem. Int. Ed. 2013, 52, 12483 for his Obituary) started a series of Reviews on organosodium and organopotassium compounds (such as phenylsodium or benzylpotassium). This first instalment concentrated on the properties, synthesis, and reactions of these compounds, including replacement of the metal and rearrangements.
In the Communications section, F. Jellinek et al. reported the first synthesis of allylbis(cyclopentadienyl)titanium(III), which involved the reaction of [(C5H5)2TiIVCl2] and allyl Grignard reagents to form the product as purple crystals. G. Scheibe et al. used proton NMR measurements to investigate internal rotation in cyanine dyes. The NMR spectra of N,N-dimethyl-substituted dyes showed two signals of equal intensity for the two methyl groups, thus confirming that internal rotation is hindered.
Read more in Issue 4/1964.
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2014, 53, No. 09, 2266
Vitamin B12 had at that time been only partially chemically synthesized (the total synthesis was first published in 1973), and a Review by K. Bernhauer et al. summarized the latest developments in the field, including partial syntheses, coenzyme forms, and enzymatic functions. A Review by Albert Eschenmoser on the origin of the molecular structure of vitamin B12 was published in our Angewandte’s Centenary Issue (Angew. Chem. Int. Ed. Engl. 1988, 27, 5–39).
Emanuel Vogel published a Communication on the properties of the cyclodecapentaene system. The system contains 10 π electrons and can thus be expected to have an aromatic character. The proton NMR spectrum of 1,6-methanocyclodecapentane showed it to have a strong ring current, however, it shows olefinic reactivity and cannot be classified as a classical aromatic compound.
Georg Wittig reported a new synthesis of tetraarylphosphonium salts. Reactions of triarylphosphines and o-fluorophenyllithium with either fluorene or methyl iodide at −40 °C resulted in the corresponding tetraarylphosphonium salt or its o-methyl derivative.
Max Schmidt reported the synthesis of 1,1,1,3,3,3-hexamethyldigermazane ((CH3)3Ge-NH-Ge(CH3)3). The reaction of trimethylgermanium chloride with ammonia produced the target compound as a colorless liquid. Reaction of dimethylgermanium dichloride under the same conditions resulted in the formation of [(CH3)2GeCl]3N.
Read more in Issue 3/1964.
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2014, 53, No. 05, 1184
Defensive substances was the topic of a Review by H. Schildknecht. In this case, the substances were the compounds used for defensive secretion by arthropods, including beetles, earwigs, and millipedes. Analysis of the defensive substances showed them to contain quinones, carboxylic acids, and aromatic aldehydes.
Rolf Huisgen reported his latest results on 1,3-dipolar cycloaddition reactions in two Communications, including the reactions of either azlactones (oxazolones) or mesoionic compounds as 1,3-dipoles in the synthesis of functionalized pyrroles. He also summarized kinetic investigations into the valence tautomerism of cyclooctatetraene in a Review.
Ernst Otto Fischer, who shared the 1973 Nobel Prize in Chemistry with Geoffrey Wilkinson, also published two Communications—on the topic of dicyclopentadienyl complexes. The first report was on the synthesis of dicyclopentadienyleuropium by reacting metallic europium with cycopentadiene in liquid ammonia, and the second dealt with the reaction of [C5H5MoC6H6(CO)]PF6 with hydride ions to form the π complex C5H5MoC6H5. For an account of the history of sandwich complexes, see Angew. Chem. Int. Ed. 2012, 124, 6052–6058.
Heinz Staab reported the synthesis of the hitherto elusive formyl chloride on a preparative scale by the reaction of 1-formylimidazole with HCl at −60°C in chloroform. The synthesis is particularly practical as the imidazolium chloride byproduct precipitates from the solution and can be removed by filtration.
Read more in Issue 2/1964.
- 50 Years Ago ...
Angew. Chem. Int. Ed. 2014, 53, No. 01, 27
Manfred Eigen, who was awarded the 1967 Nobel Prize in Chemistry together with Ronald G. W. Norrish and George Porter, published a classic Review on proton transfer mechanisms and the modes of acid–base and enzymatic catalysis. The systems discussed include proton mobility in ice crystals, and pseudo acids. A review of his latest book entitled From Strange Simplicity to Complex Familiarity: A Treatise on Matter, Information, Life and Thought appeared in Issue 52/2013.
Albert Eschenmoser et al. reported on the use of N,N-dimethylformamide dineopentylacetal for the esterification of carboxylic acids with benzyl alcohols. Use of this reagent is advantageous as only one equivalent of the alcohol is required and only volatile by-products are produced in some cases. Eschenmoser’s most recent contribution is a grand Review on prebiotic chemistry (Angew. Chem. Int. Ed. 2011, 50, 12 412).
The preparation of pure disulfur monoxide was reported by P. W. Schenk and R. Steudel, who reacted thionyl chloride with metal sulfides that act as dehalogenating reagents. The reaction of thionyl chloride and silver sulfide provided disulfur monoxide in 96 % purity.
H. Rheinheckel published two Communications on triethylaluminum, and reported how an ice-cold mixture of triethylaluminum and carbon tetrachloride exploded when the ice bath was taken away. The explosion was so violent that the hood was destroyed and not a single fragment of glass could be found.
Read more in Issue 1/1964.