Intermetallic Communication through Carbon Wires in Heterobinuclear Cationic Allenylidene Complexes of Chromium
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- 作者：Normen Szesni ; Matthias Drexler ; Jö ; rg Maurer ; Rainer F. Winter ; Fré ; dé ; ric de Montigny ; Claude Lapinte ; Stefan Steffens ; Jü ; rgen Heck ; Bernhard Weibert ; Helmut Fischer
- 刊名：Organometallics
- 出版年：2006
- 出版时间：November 20, 2006
- 年：2006
- 卷：25
- 期：24
- 页码：5774 - 5787
- 全文大小：312K
- 年卷期：v.25,no.24(November 20, 2006)
- ISSN：1520-6041
文摘
The reaction of [(CO)5M(THF)] (M = Cr, W) with lithiated 2-ethynylquinoline followed by alkylationof the resulting alkynylpentacarbonylmetalate with [R3O]BF4 (R = Me, Et) gives allenylidene complexesin which the terminal carbon atom of the allenylidene chain is part of an N-alkylated quinoline ring. Thereaction of [(CO)5M(THF)] (M = Cr, W) with lithiated 2-ethynylpyridine derivatives, Li[C
CC5H4BrN], and [Et3O]BF4 affords allenylidene complexes that contain a terminal six-membered N-heterocyclebrominated at the 5- or 6-position. Various alkynyl groups can be introduced into the 5-position of thering through [PdCl2(PPh3)2]-catalyzed coupling of the 5-bromo-substituted allenylidene complexes withthe terminal alkynes HCCR' (R' = TMS, Ph, C10H21, 4-C6H4-CCPh, 4-C6H4-CCH, Fc (Fc = (C5H4)FeCp), 4-C6H4-CCFc, 4-C6H4-CCC6H4CCFc). The analogous replacement reaction of the 6-bromo-substituted chromium complex with HCCFc yields the corresponding 6-ferrocenylalkynyl-substitutedcomplex. Desilylation of [(CO)5Cr=C=C=C(CH)2C(CCSiMe3)CH NEt] (6a) gives [(CO)5Cr=C=C=C(CH)2C(CCH)CH NEt] (15a). CuI-catalyzed coupling of 15a with {M}-Br ({M} = Ru(CO)2Cp, Fe(CO)2Cp*) affords the binuclear complexes [(CO)5Cr=C=C=C(CH)2C(CC-{M})CH NEt]. Thesymmetrical binuclear complex is formed by oxidative coupling of 15a with [Cu(OAc)2]. The attachmentof a ferrocenyl group to the chromium center via PPh2 to give cis-[(CO)4(Ph2PFc)Cr=C=C=C(CH)4 NEt] is achieved via displacement of a cis-CO ligand in [(CO)5Cr=C=C=C(CH)4 NEt] by PPh2Fc. On additionof Co2(CO)8 to [(CO)5Cr=C=C=C(CH)2C(CCPh)CH NEt] a Co2(CO)6 unit adds to the CC bond toform a trinuclear complex. The ferrocenyl unit in [(CO)5Cr=C=C=C(CH)2C(CCR)CH NEt] (R = Fc,C6H4CCFc, C6H4CCC6H4CCFc) is readily oxidized. Spectroelectrochemical studies (IR, UV/vis)confirm that in the oxidized form there is strong electronic communication of the ferrocenyl group withthe (CO)5Cr unit.
CC5H4BrN], and [Et3O]BF4 affords allenylidene complexes that contain a terminal six-membered N-heterocyclebrominated at the 5- or 6-position. Various alkynyl groups can be introduced into the 5-position of thering through [PdCl2(PPh3)2]-catalyzed coupling of the 5-bromo-substituted allenylidene complexes withthe terminal alkynes HCCR' (R' = TMS, Ph, C10H21, 4-C6H4-CCPh, 4-C6H4-CCH, Fc (Fc = (C5H4)FeCp), 4-C6H4-CCFc, 4-C6H4-CCC6H4CCFc). The analogous replacement reaction of the 6-bromo-substituted chromium complex with HCCFc yields the corresponding 6-ferrocenylalkynyl-substitutedcomplex. Desilylation of CSiMe3)CHCH)CHC-{M})CHCPh)CHC bond toform a trinuclear complex. The ferrocenyl unit in CR)CHCFc, C6H4CCC6H4CCFc) is readily oxidized. Spectroelectrochemical studies (IR, UV/vis)confirm that in the oxidized form there is strong electronic communication of the ferrocenyl group withthe (CO)5Cr unit.