A Route to Highly Functionalized β‑Enaminoesters via a Domino Ring-Opening Cyclization/Decarboxylative Tautomerization Sequence of Donor–Acceptor Cyclopropanes with Substituted Malononitriles

An
unprecedented and domino synthetic strategy for the synthesis of highly
functionalized carbocyclic β-enamino­esters bearing an
all-carbon quaternary center via Yb­(OTf)3-catalyzed ring-opening
cyclization/decarboxylative tautomerization of donor–acceptor
cyclo­propanes with 2-alkyl malono­nitriles in excellent
yields is described. The products are obtained as a single diastereo­mer
in most cases where the nitrile and aryl groups are aligning in a cis orientation across the ring.