Chiral silicon-bridged 2-(N,N-dialkylamino)ethyl-substituted indenes as potential precursors for ansa-zirconocenes

Abstract

Chiral amino-functionalized silicon-bridged indene derivatives 4a–4c were synthesized from 3-(2-(N,N-dialkylamino)ethyl)indenes 2a–2c. The C-Si coupling reactions are regioselective, leading exclusively to the formation of 1,3-disubstituted isomers in a rac/meso ratio of 1:1, as indicated by NMR spectroscopy. The solid-state structure of the dimethylsilyl-bridged bisindene (R,R)-4a is described. The formation of corresponding ansa-zirconocenes via amine elimination chemistry was monitored by 1H NMR spectroscopy.Key words: amino-functionalized indenes, silicon-bridged, ansa-metallocenes, chirality, regioselectivity, amine elimination chemistry.