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Koordinationschemie Perhalogenierter Cyclopentadine und Alkine, XV. Systematischer Aufbau von fünffach ringsilylierten Cyclopentadienyl‐mangan‐Komplexen aus [C 5 Br 5 ]Mn(CO) 3 . Molekülstruktur von [C 5 Br 3 (SiMe 3 ) 2 ]Mn(CO) 3
Author(s) -
Sünkel Karlheinz,
Hofmann Julian
Publication year - 1993
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19931260806
Subject(s) - chemistry , cyclopentadienyl complex , crystal structure , manganese , bromine , silylation , medicinal chemistry , electrophile , stereochemistry , molecule , crystallography , catalysis , organic chemistry
Coordination Chemistry of Perhalogenated Cyclopentadienes and Alkynes, XV [1] . – Systematic Generation of Fivefold Ring‐Silylated Cyclopentadienyl Manganese Complexes from [C 5 Br 5 ]Mn(CO) 3 . Molecular Structure of [C 5 Br 3 (SiMe 3 ) 2 ]Mn(CO) 3 [C 5 Br 5 ]Mn(CO) 3 reacts in a sequence of alternate bromine‐lithium exchange reactions and electrophilic silylations by SiMe 3 Cl or SiMe 3 OSO 2 CF 3 to give [C 5 Br 5 ‐ n (SiMe 3 ) n ]Mn(CO) 3 , where n = 1 ( 1 ), 2 ( 2 ), or 3 ( 3 ). A crystal structure determination of 2 shows the two silyl substituents in the relative 1,3‐orientation. Addition of one or two equivalents of BuLi and SiMe 2 HCl to a solution of 3 yields [C 5 Br 2 ‐ n (SiMe 3 ) 3 ‐(SiMe 2 H) n ]Mn(CO) 3 with n = 1 ( 4 ) and 2 ( 5 ), respectively. If 1 is treated twice with 2 eq. of BuLi and then 2 eq. of SiMe 2 HCl, a further pentasilylated compound, [C 5 (SiMe 3 )(SiMe 2 H) 4 ]‐Mn(CO) 3 ( 6 ), is obtained. In situ chlorination of [C 5 (SiMe 2 H) 5 ]Mn(CO) 3 or 6 with PdCl 2 , followed by addition of MeMgCl, yields after chromatography an inseparable mixture of [C 5 (SiMe 3 ) 4 X]Mn(CO) 3 compounds, where X = H ( 7a ), SiMe 2 H ( 7b ), and SiMe 3 ( 7c ).