Synthese und Röntgenstruktur einer Triafulvalen-Vorstufe

Abstract

Triafulvalene precursors 3b and 3c have been synthesized by Cu^II-catalyzed 'carbene dimerization' of cyclopropyl carbenoids (obtained by halogen-lithium exchange of 1,1-dibromo-2-(phenylthio)-3-(trimethylsilyl)cyclopropane (2b; see Scheme 2) in moderate yields. Diastereoselectivity of the central step 2b → 3b is low. An X-ray analysis of the predominantly formed trans-anti isomer has been performed.