Catalytic Cycloisomerization of Enyne Diesters Derived from Biaryls and Related Substrates

Abstract

Enyne diesters derived from biaryls and related substrates undergo intramolecular [2+2]-cycloaddition and concomitant cyclo-reversion when treated with 10 mol% In(OTf)3 in 1,2-dichloroethane. This enyne metathesis type cycloisomerization reaction enables the synthesis of phenanthrene, benzophenanthrene, benzotetraphene and other polycyclic (hetero)aromatic compounds bearing a synthetically useful diethyl β-(hetero)arylidene malonate moiety in a step- and atom-economic manner. In(OTf)3-catalyzed two independent intramolecular cycloisomerization on substrates 5 a and 5 b provides direct access to benzotetraphenes 6 a and 6 b containing bis(diethyl β-phenylmethylene malonate) moiety. Tetrasubstituted vinylidene malonate 4 a, substiututed by two different aromatic groups, is stereoselectively converted into E- and Z-isomer of triaryl group containing all carbon tetrasubstituted olefins (8 a, 8 a′ and 8 b) via Pd-catalyzed stereoselective decarboxylative arylation reaction. © 2023 Wiley-VCH GmbH.