Abstract
The Friedel–Crafts reaction of (η4-tetraphenylcyclobutadiene)(η5-carbomethoxycyclopentadienyl)cobalt with acid chlorides/aluminum chloride resulted exclusively in para-phenyl acylation. Both monoacylated (1.1 equiv of RCOCl/AlCl3) and tetraacylated products (>4 equiv of RCOCl/AlCl3) were synthesized. Reaction of PhCC(o-RC6H4) (R = Me, i-Pr) with Na(C5H4CO2Me) and CoCl(PPh3)3 gave predominantly (η4-1,3-diaryl-2,4-diphenylcyclobutadiene)(η5-carbomethoxycyclopentadienyl)cobalt metallocenes (1,3-[trans] vs 1,2-[cis] selectivity up to 6:1). Conformational control of Friedel–Crafts reactions on the major isomers gave exclusively para-acylation of the unsubstituted phenyl groups.
Original language | English |
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Pages (from-to) | 894-897 |
Number of pages | 4 |
Journal | Organic Letters |
Volume | 14 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2012 |