摘要:
The codimerization of quadricyclane (QC), the valence isomer of norbornadiene (NBD), with norbornene compounds was studied in the presence of Pd(0) complexes. Codimerization of QC with norbornene, 5-methyl- and 5-methylenenorbornene, exo-tricyclo[3.2.1.0(2,4)]octene-6, tetracyclo[4.2.0.0(2,4).0(3,7)]nonene-8, and penta- and hexacyclic NBD dimers was carried out in the presence of PPh3-activated Pd2(DBA)3.CHCl3 to afford a new class of hexa- to nonacyclic strained hydrocarbons with exo- and endo-tetracyclo[4.2.0.0(2,4).0(3,7)]nonane fragments.