Neue Synthesen Mit Ubergangsmetallkomplexen, X. Mitt / New Syntheses With Transition Metal Complexes, X.

Abstract

The X-ray determination (W. HOPPE and coworkers) of the structure of the Rh-complex from tris- [triphenylphosphin] -rhodiumchloride and 1.2-bis- [phenylpropinoyl] -benzene (synthesized by E. MÜLLER and coworkers) shows a molecular structure with a metallocyclopentadiene system formed by both C≡C groups and the Rh atom by ring closure. The coordination number of rhodium is 5. The reaction path leading to the complex is discussed, and it is pointed out that the complex does not reacting with typical dienophiles but with acetylenes.

Ru(ii)-catalyzed [2 + 2 + 2] cycloaddition of 1,2-bis(propiolyl)benzenes with monoalkynes leading to substituted anthraquinonesElectronic supplementary information (ESI) available: experimental procedures and analytical data. See http://www.rsc.org/suppdata/cc/b3/b301762a/

“…As previously proposed for the ruthenium-catalyzed cycloaddition of 1,6-diynes and monoalkynes, the present anthraquinone annulation probably proceeds via bicyclic ruthenacycle intermediate. 7,8 If this is the case, the terminal phenyl groups on the diketodiyne might stabilize the ruthenium-carbon bonds and thus reduce the reactivity of the expected ruthenacycle 4. In good agreement with these analyses, 4 was formed by simply stirring the solution of Cp*RuCl(cod) and a slight excess of 1c in DCE at room temperature for 0.…”