A new entry towards diastereomeric C1,C2,C3-functionalized [3]ferrocenophanes using a solid state mediated double 1,4-Michael addition type ring closing approach

Abstract

Unusual diastereomeric C¹,C²,C³-functionalized carba[3]ferrocenophanes with two stereogenic centres have been obtained using a ring closing reaction, based upon double/two-fold 1,4-Michael addition under solid support conditions. The [3]ferrocenophanes are the first known structures among the class of saturated tri-functionalized carba[3]ferrocenophanes. One meso-type (1S,2s,3R) and two enantiomeric (1S,3S and 1R,3R) [3]ferrocenophanes have been identified and characterized. A mechanism has been proposed to understand the possible mode of nucleophilic attack that led to the unusual stereoisomeric tri-functionalized ferrocenophanes. The heterocycle functionalized ferrocenophanes with three pyridyl chains oriented in different directions have been used as antennas to explore the sensing of picric acid selectively at the ppb level.