Two‐Step Synthesis of Heptacyclo[6.6.0.0^2,6.0^3,13.0^4,11.0^5,9.0^10,14] tetradecane from Norbornadiene: Mechanism of the Cage Assembly and Post‐synthetic Functionalization

Abstract

As elective and scalable two-step approacht ot he dimerization of norbornadiene (NBD) into its thermodynamically most stable dimer,heptacyclo[6.6.0.0 2,6 .0 3,13 .0 4,11 .0 5,9 .0 10,14 ] tetradecane,(HCTD) is reported. Calculations indicate that the reaction starts with the Rh-catalyzed stepwise homo Diels-Alder cyclisation of NBD into its exo-cis-endo dimer.T reatment of this compound with acid promotes its evolution to HCTD via a[1,2]-sigmatropic rearrangement. The assemblies of 7,12-disubstituted cages from 7-(alkyl/aryl) NBDs,aswell as the selective post-synthetic CÀHf unctionalization of the core HCTD scaffold at position C1, or positions C1 and C4 are described.

Hexacyclotetradecenes as Polycyclic Fused exo-Norbornene Monomers: Synthesis of Cyclic Olefin Copolymers via Ti-Catalyzed Efficient Polymerization

“…30,31 NBD has unique diene -bonds that chelate to the transition-metal center; hence, it undergoes various transition-metal-catalyzed cycloaddition reactions to yield polycyclic hydrocarbons. Among these reactions, the dimerizations of NBD afford various cyclic hydrocarbon products (a diene, 32,33 monoalkenes, [34][35][36][37][38] and saturated dimers 39 ), some of which yield reactive cyclopropane moieties. We have previously reported the synthesis of cyclopropane-containing COPs through the ROMP of four stereoisomeric NBD dimers containing a polymerizable norbornenyl group and a cyclopropane moiety.…”