Efficient synthesis of macrocyclic paracyclophanes by ring-closing metathesis dimerization and trimerization reactions

Ring-closing metathesis reactions of para-disubstituted aromatic substrates produced macrocyclic [n.n]-, and [n.n.n]paracyclophanes efficiently through dimerization and trimerization reactions. Sufficiently long alkyl chains allowed direct monocyclizations to yield [n]paracyclophanes. A small library of paracyclophanes were generated by the combinatorial cross-metathesis approach.