Facile Synthetic Access to Multisubstituted Benz[f]indenones and Their Application as Ligands to the First Synthesis of Group(IV) Metallocene Complexes

Abstract

[reaction: see text] A very efficient method for the synthesis of benz[f]indenone derivatives was developed. This method allows the introduction of a variety of substituents to a molecule. The first zirconocene compound of benz[f]indene was synthesized.

Synthesis of zirconocenes bearing benz[f]indenyl ligand and their use as a catalyst in ethylene polymerization

“…Substituted benz [f]indenes [5] and unsubstituted benz [f]indene [7] were prepared by the procedure of the literature. The benz [f]indenes having substituents were not soluble in diethyl ether but soluble in THF at À78°C.…”

“…The activities of unsubstituted benz [f]indenyl zirconium complexes (4)(5)(6) were greater than those of substituted benz [f] (39 · 10 6 g/mol of Zr h) was observed for 5 and 3 shows the lowest activity (7.9 · 10 6 g/mol of Zr h) with the highest molecular weight, 10.3 · 10 5 . Interestingly, the activity of 6 and the molecular weight of polyethylene produced by 6 are comparable to that of Cp 2 ZrCl 2 but 4 and 5 have much higher activities.…”

“…The reactor was heated at 130°C for 18 h. After the reactor was cooled to rt and excess gas was relieved, the solution was transferred into a flask and then evaporated to dryness. The residue was chromatographed on a silica gel column eluting with hexane and ethyl acetate (v/v, 8:1 5,148.5,147.6,131.3,128.7,128.4,127.3,127.2,126.9,125.8,118.2,118.1,85.8,85.1,57.5,52.6,14.7,14.4;IRm (C@O) 1698 cm À1 ; HRMS for C 21 H 18 O 2 : Calc. 302.1307, obsd.…”

“…Benz [f]indenyls, isomer to fluorenyls, have not been used as alternatives or substitutes for Cp until we recently reported [5] the first synthesis of zirconium complexes of benz [f]indenyl ligands. There had been some efforts to synthesize metallocenes bearing benz [f]indenyls [6].…”

Aromaticity and Magnetic Properties of 1‐ and 2‐Indenones and Their Aza Derivatives

“…In the 2‐one series, the metal complexes of the dianion of 1 have been reported,16 compound 2 has been classified by Padwa as antiaromatic17 and quasi‐antiaromatic,18 compound 3 is commercial but most references correspond to patents and only two to journals 19,20. In the second series, the 1‐ones, derivatives of 4 are known21,22 and at least two theoretical papers discuss its reactivity;23,24 to our knowledge, nothing is known about 5 , but 6 , although unknown itself, is related to indigo25 and other derivatives 26–28. Finally 7 has been prepared electrochemically by oxidation and its reactivity has been studied 29,30…”