Abstract EN:

In our research work, we have been involved in the development of new catalytic reactions of unsaturated bicyclic[2. 2. 1] compounds and alkynes. An efficient palladium catalysed addition of terminal alkynes across one double bond of norbornadiene resulting in the selective formation of exo-5-alkynyl-bicyclo[2. 2. 1] hept-2-enes is reported. The reaction show general applicability to various functionalized alkynes and bicyclo[2. 2. 1]hepta-2,5-dienes. Mechanistic insights into these reaction are also provided on the basis of labelling experiments. A new synthesis of 8,9-disubstituted deltacyclenes via a [2+2+2] cycloaddition of norbornadiene with disubstituted alkynes has been achieved with ruthenium catalyst systems. The reaction is applicable to various disubstituted alkynes and 7-substituted norbornadienes. The Homo-Diels Alder Reaction becomes more efficient when the C7-substituent is an aryl or alkyl group. Finally, an efficient catalyst system combining CpRuCl(PPh3)2 and MeI allow the [2+2] cycloaddition of norbornadiene or norbornene with various disubstituted alkynes providing functionalized tricyclic compounds. We have shown that the activation of CpRuCl(PPh3)2 with methyl iodide generates in situ CpRuI(PPh3)2 as the key catalyst.