488791-70-4Relevant academic research and scientific papers
Synthesis of polycyclic polyfunctionalized carbocycles by a cobalt(I)-initiated tandem Diels - Alder reaction sequence
Hilt, Gerhard,Lueers, Steffen,Polborn, Kurt
, p. 317 - 327 (2001)
The cobalt(I)-catalyzed neutral Diels - Alder reaction of acyclic 1,3-dienes with conjugated enynes can be used to generate secondary dihydroaromatic 1,4,8-trienes containing a 1,3-diene substructure, in good yields under mild reaction conditions. These 1,3-dienes can be converted, with reactive dienophiles in a tandem normal Diels - Alder reaction, into polycyclic compounds. In a similar tandem Diels -Alder sequence, the cobalt-catalyzed neutral homo Diels - Alder reaction of 2,5-norbornadiene can be used to generate polycyclic cycloaddition adducts. A sequential triple Diels - Alder reaction sequence can be realized when norbornadiene is reacted with the excess of the conjugated enynes under cobalt(I) catalysis. In a homo Diels - Alder, neutral Diels - Alder, normal Diels - Alder reaction sequence, the intermediately formed adducts are reacted with activated dienophiles to yield polycyclic compounds in a short sequence. The structures of several products were established by X-ray analysis. This showed that predominantly endo-products are formed in the tandem reaction sequences, while the exo-product becomes predominant in the triple Diels - Alder reaction sequence.
Rhodium- or copper-catalysed CH-insertion of carbenoids into dihydro-aromatic compounds and acyclic 1,4-dienes
Hilt, Gerhard,Galbiati, Fabrizio
, p. 3589 - 3596 (2008/03/14)
A straightforward reaction sequence consisting of a cobalt-catalysed Diels-Alder reaction for the generation of dihydroaromatic compounds and a rhodium- or alternatively a copper-catalysed CH-insertion reaction of carbenoids from diazo esters generates highly substituted benzene derivatives. When acyclic 1,4-dienes are synthesised by a cobalt-catalysed 1,4-hydrovinylation reaction, the rhodium-catalysed conversion with diazo esters leads to cyclopropanation rather than CH-insertion products. Georg Thieme Verlag Stuttgart.
