18180-70-6Relevant academic research and scientific papers
An one-pot synthesis of semibullvalenes and its mechanism
Sauer, Juergen,Baeuerlein, Peter,Ebenbeck, Wolfgang,Schuster, Johann,Sellner, Ingeborg,Sichert, Heinz,Stimmelmayr, Horst
, p. 791 - 801 (2007/10/03)
1,2,4,5-Tetrazines 7 readily react with 3,3′-bicyclopropenyl 8 in a cycloaddition-cycloelimination sequence to give 3,4-diazanorcaradienes 9 with endo configuration of the methyl group at C-7. On gentle heating in inert solvents, these 3,4diazanorcaradienes 9 are cleanly transformed into semibullvalenes 11. This reaction sequence can also be performed as a one-pot method. Kinetic investigations and comparisons with two model systems are in agreement with the proposed reaction mechanism.
The cycloaddition-cycloelimination pathway to homotropilidenes - Synthesis and properties of homotropilidenes
Sauer, Jürgen,B?uerlein, Peter,Ebenbeck, Wolfgang,Dyllick-Brenzinger, Rainer,Gousetis, Charalampos,Sichert, Heinz,Troll, Theodor,Wallfahrer, Uwe
, p. 2639 - 2657 (2007/10/03)
The cycloaddition-cycloelimination reaction sequence between 3,6-disubstituted 1,2,4,5-tetrazines 9 and various cyclopropenes 10 provides 3,4-diazanorcaradienes 11, which undergo [4+2] cycloadditions with additional cyclopropenes 10 to form tetracyclic azo compounds 12. Photolysis of these compounds, with accompanying loss of nitrogen, affords homotropilidenes (bicyclo[5.1.0]octa-2,5-dienes) 13-26. Substituents at various positions of the homotropilidene skeleton have been observed to exert significant influences on the Cope rearrangement rate and, in cases of unsymmetrically substituted homotropilidenes, on the equilibrium positions.
