Metal Complexes with Macrocyclic Ligands,VI. The role of substituents on the complexation rate of transition metal ions with several 1,4,7,10-tetraazacyclotridecanes

12,12-Dimethyl-1,4,7,10-tetraazacyclotridecane (I), 11,13-dimethyl-1,4,7,10-tetraazacyclotridecane (II), 11,11,13-trimethyl-1,4,7,10-tetraazacyclotridecane (III) and 1,4,7,10,12,12-hexamethyl-1,4,7,10-tetraazacyclotridecane (IV) have been synthesized and their properties are described. While the Ni²⁺ and Cu²⁺ complexes of I–III have square planar geometries, those of IV are pentacoordinate according to their absorption spectra. Similarly, while the Co²⁺ complex of I is octahedral and readily oxygenated, the analogous complex with IV is pentacoordinate and not sensitive to oxygen. The rate of complexation of these ligands with Cu²⁺ and Ni²⁺ decreases in the order I > II > III ? IV, indicating that the number as well as the position of the methyl groups are important. Finally for Cu²⁺ the formation of the thermodynamic stable end product is slown down by methyl substitution in α-position to the coordinating nitrogen atoms (ligand II and III) so that an intermediate can be observed, whereas with I Cu²⁺ directly forms the end product.     

1, 6-Addition von Chlorsulfonylisocyanat. Vorläufige Mitteilung

A 1, 6-addition of sulfonyl chloride isocyanate to 5, 7-dimethyl-8-methylidene-tricyclo[3.2.1.0^2,7]oct-3-en-6-one ( 1 ) produced the new tricyclic skeleton of 4a, 6-dimethyl-2, 5-dioxo-2, 3, 4a, 5, 6, 8a-hexahydro-1H-6, 4-methenoquinoline-1-sulfonyl chloride ( 2 ). The structure of the new aza-tricyclic species has been elucidated by X-ray analysis.     

Dimerisierung von benzocyclobuten zu 1-ethyl-9,10-dihydrophenanthren unter dem einfluss von natrium-kalium-legierung in tetrahydrofuran

Benzocyclobutene is cleaved by sodium-potassium alloy in THF at a C_aryl-CH₂ bond whereby in contrast to the corresponding reaction with lithium a dimeric product, 1-ethyl-9,10-dihydrophenanthrene, is formed.     

Heterodiamantane und strukturell verwandte Verbindungen II. Pentacyclische Diäther der C10-Reihe: 5,12-Dioxapentacyclo-[6.4.0.02,6.04,9]dodecan und 4,12-Dioxapentacyclo[6.3.1.02,7.03,10.05,9]- dodecan

In connection with studies on heterodiamantanes and structurally related compounds the two novel pentacyclic diethers 9 and 10 were prepared starting from the photo-dimer 8 of cyclopentadienone. All three compounds have as common features a central carbocyclic 6membered ring with four axial alkyl substituents and two oxygen function in 1,4-position. The diether 9 was obtained on the one hand from the intermediate tetracyclic unsaturated alcohol 23 by intramolecular addition, catalyzed either by acid or base (scheme 3), and on the other hand from the tetracyclic diol 32 or the dibromoketones 34 (via 38 ) and 35 (via 39 ) by intramolecular substitution (schemes 4 and 5). The synthesis of the isomeric diether 10 was achieved by intramolecular substitution of the tetracyclic diol 33 (scheme 4). Diether 9 is thermodynamically more stable than 10 . The latter was easily isomerized to the former on treatment with concentrated sulfuric acid in benzene.