[2 + 2] Dimerization of norbornadiene and its derivatives in the presence of nickel complexes and zinc metal

Nickel-Catalyzed [2+2] Cycloaddition of Alkynes with Activated Cyclic Alkenes: Synthesis and Novel Ring Expansion Studies of Cyclobutene Products

“…On the other hand, NiBr 2 /Zn and [Ni(cod) 2 ] (cod cycloocta-1,5-diene) gave not only the cross- [22] cycloadduct, but also the product (10) from homo- [22] cycloaddition of oxabenzonorbornadiene. [19] No homocycloaddition product was observed when nickel phosphine systems were used. Given the known organometallic chemistry of nickel and the structure of the products observed, we propose the mechanism depicted in Scheme 3 to account for the present nickel-catalyzed [22] cycloaddition.…”

Ruthenium-Catalyzed Dimerization of 7-Oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylates

“…Further studies of this reaction have been carried out involving other Ni and Co catalysts as well as Fe, Cr, and Rh catalysts. Regardless of the catalyst system employed, only trans norbornadiene dimers were obtained as products, confirmed by 1 H coupling constants . The dimers resulting from the Rh catalyzed reactions were minor products in the formation of trimers and other more complex cycloadducts. , Despite the many literature examples of the dimerization of norbornadiene, Cheng and co-workers provided the only example of the dimerization of an oxabicyclic alkene.…”

“…Regardless of the catalyst system employed, only trans norbornadiene dimers were obtained as products, confirmed by 1 H coupling constants. 24 The dimers resulting from the Rh catalyzed reactions were minor products in the formation of trimers and other more complex cycloadducts. 25,26 .…”

“…The exo-trans-exo conformation was predicted based on the 1 H and 13 C NMR spectra and confirmed using X-ray diffraction. 24 Our interest in oxabicyclic alkenes and the lack of investigation into the dimerization of these compounds lead to our study of the Ru catalyzed dimerization of 7-oxabicyclo-[2,2,1]hepta-2,5-diene-2,3-dicarboxylates. Our investigations began by screening various Ru catalysts to determine their efficacy in this dimerization (Table 1).…”

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

“…allow for diverse functionalization. Over the years, several interesting transformations have been investigated such as cycloadditions 4 [18][19][20][21][22][23], dimerizations 3 [24][25][26][27], isomerizations [28][29][30][31], among other reactions that have been reported [32][33][34][35][36][37][38]. The nucleophilic ring-opening reactions of heterobicyclic alkenes are of particular interest [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53], as they provide access to a broad family of synthetic building blocks bearing multiple stereocenters in a single step 2 [54].…”