Cuprate Addition to a 6-Substituted Pentafulvene - Preparation of sec-Alkyl-Substituted Titanocene Dichlorides and Their Biological Activity.

The copper-catalysed (10 mol-% CuBr ·SMe2, CuCN ·LiCl or CuI/PPh3) addition of RMgBr to the pentafulvene 1-(cyclopenta-2,4-dien-1-ylidenemethyl)-2-methoxybenzene allows the formation of cyclopentadienyl derivatives with α-CHR(2-MeOPh) sidechains (R = Me, Et, nBu, iBu, allyl, Ph) without H- transfer. The deprotonation of these sec-alkyl-substituted cyclopentadienyls followed by the addition of TiCl4 allows the isolation of TiCl2{η5-C5H4CHR(2-OMePh)} as rac/ meso mixtures that show activity against human colon, breast and pancreatic cell lines (GI50 2.3-42.4 μ M). [ABSTRACT FROM AUTHOR]