Site-Selectivity in the Fe+-Mediated C?H/C?C Bond Activation of Aldimines Short Communication

It is demonstrated for the first time that the site-selectivity for the Fe⁺-mediated C? H bond activation of aldimines R¹N?CHR² (R¹, R² = alkyl) involves the alkyl chain R¹ by a factor ≥ 12 in comparison to the alkenyl part R². This finding explains previous observations that dehydrogenation of intermediates formed by alkene loss from either R¹ or R² of R¹N?CHR²/Fe⁺ preferentially involves the alkyl part.     

Synthese O- und C-alkylierter Indoxylderivate

Zusammenfassung Der Indoxyl-2-carbonsäure-ester (4) wird mit Allylchlorid und Dimethylallylbromid in der 2-Stellung zu6 bzw.7 alkyliert. In geringer Ausbeute dargestelltes 4-Diazo-2-methyl-buten-(2) (11) alkyliert4 ebenfalls in2-Stellung, jedoch unter Inversion der Substituenten zu2.Eine Alkylierung von4 am Sauerstoff erreicht man mit Diazomethan, Diazoacetaldehyd-diäthylacetal (zu25) und 4-Diazo-3-methyl-3-äthoxycarbonyloxy-buten-(2) (zu17). Von hier aus wurden die Verbindungen16–20 dargestellt. Die Bromwasserstoffabspaltung aus20 führt nicht zu der gewünschten Verbindung21, sondern zu22, das nicht zu einer Allylumlagerung fähig ist.Mit 1 Abbildung.Herrn Prof. Dr.F. Wessely zum 70. Geburtstag in Verehrung gewidmet.     

7,15-Diazadispiro[5.1.5.3]hexadecan und Derivate, 3. Mitt.: Carbamidino- und Thiocarbamoylderivate von 14-Imino-7,15-diazadispiro[5.1.5.3]hexadecan

14-Imino-7,15-diazadispiro[5.1.5.3]hexadecane reacts with carbodiimides and isothiocyanates to form 11 adducts. The assumption, that additions take place at the 14-imino group, is supported by spectroscopic data.

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H. Egg, 2. Mitt., Mh. Chem.106, 1175 (1975)     

Considerations about the sol-gel process: From the classical sol-gel route to advanced chemical nanotechnologies

This paper was given on occasion of receiving the first Life Time Award by the International Society on Sol-Gel Science and Technology. Its intention is to provide an insight on the development of this field, its driving forces and especially on its impact on application and industrial technologies. The motivation of the work carried out in the last decades is that in the early days of the sol-gel technologies, where this route started to interest industry as well as scientists, the author got interested in a field which was clearly application-driven and strongly anchored in the material scientist community rather than in fundamental chemistry. If one is talking about application-oriented technologies, of course, markets and industrial needs have to be taken into consideration, because the restrictions or bottle-necks, but also chances provided by economical needs strongly may govern the field. In opposition to these fields, only driven by science, may not have these restrictions as far as it is possible to raise funds for the scientific work. For this reason, the attempt is made to point out the connections between application and science in the sol-gel field. Since I am working in the sol-gel field since 1975, strongly focused on industrial applications, it should be understandable that many of my own development examples are used to demonstrate this way. Another problem, of course, is connected to the sol-gel field: This is a question of appropriate definitions as well as to draw a clear borderline of the field. Especially in the last decade, the connection of sol-gel materials to nanostructured materials has become closer, so that it is difficult to clearly divide these fields. On the other hand, the fabrication of nanoparticles by hydrolysis and condensation processes or controlled precipitation processes can be defined as a sol-gel technology, but in many cases is just not done. This leads to the fact that in many areas, sol-gel types of processes are used, but called different. Due to the fact that the properties of small particles either in solution or dispersed in an appropriate matrix show highly interesting material properties, it would be desirable that the sol-gel community would try to interact stronger with these developments (e.g. the “particle” community). This also might include a focus of the sol-gel area a little bit more back to the routes, to material science development and engineering. According to my opinion, this would be a very interesting supplement for the field as it is represented today.     

Construction of a yeast plasmid cloning vector with high stability inSaccharomyces cerevisiae strains deficient in 2 µmDNA

PlasmidpCP1 was constructed from cloned 2 µmDNA ofSaccharomyces cerevisiae and from plasmidpJDB207. VectorpCP1 contains the completeB form of 2 µmDNA interrupted in theFLP gene, together withDNA derived from theEscherichia coli plasmidpAT153 and a low expression variant of theS. cerevisiae LEU2 gene. The new vector is lost at a low frequency from yeastcir ⁺ orcir ⁰ strains under non-selective growth conditions and is stable against rearrangements incir ⁰ strains. Its usefulness for curingcir ⁺ strains from endogenous 2 µmDNA and for their conversion tocir ⁰ strains was demonstrated.Dedicated to Professor Dr.Karl Schlögl on the occasion of his 60th birthday.     

Structure-Activity Relationships of Oxygenated Morphinans. I. 4-Mono- and 3,4-dimethoxy-N-methylmorphinans and -N-methyl-morphinan-6-ones with unusually high antinociceptive potency. Preliminary communication

The antinociceptive potency and receptor affinity of several optically active aromatic mono- and di-oxygenated N-methylmorphinans and N-methylmorphinan-6-ones, prepared from natural morphine, were determined. Thus, in order of antinociceptive potency, 4-methoxy-N-methylmorphinan-6-one ≈ 3,4-dimethoxy-N-methylmorphinan-6-one ≈ 3,4-dimethoxy-N-methylmorphinan > 4-methoxy-N-methylmorphinan ≈ 4-acetoxy-N-methylmorphinan-6-one > 4-acetoxy-N-methylmorphinan ≈ 4-hydroxy-N-methylmorphinan-6-one ≈ 4-hydroxy-N-methylmorphinan. The 4-hydroxy compounds were slightly less potent than morphine, and the 4-methoxy and 3,4-dimethoxy compounds were found to have three times the potency of morphine. 4-Methoxy-N-methylmorphinan-6-one showed an opiate receptor affinity one-third that of morphine; this is a remarkably high affinity for a non-phenolic compound.     

Magnesium

Ohne Zusammenfassung