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Zirconocene Functional Group Chemistry: Photochemical [4+4] Cycloaddition of Isoprenyl Sidechains to the Bent Metallocene Framework
Author(s) -
Greger Ingo,
Kehr Gerald,
Erker Gerhard
Publication year - 2010
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201000432
Subject(s) - chemistry , fulvene , deprotonation , metallocene , cycloaddition , transmetalation , intramolecular force , medicinal chemistry , metathesis , photodissociation , stereochemistry , photochemistry , organic chemistry , catalysis , polymerization , ion , polymer
The 4‐isoprenyl‐ and 1‐isoprenylcyclopentadienides 6a and 6b were prepared by means of a fulvene route involving a subsequent deprotonation reaction using potassium hexamethyldisilylamide. Transmetallation to zirconium or hafnium gave the respective bis(4‐isoprenyl‐Cp)MCl 2 and bis(1‐isoprenyl‐Cp)MCl 2 complexes 7a , b and 8a , b , respectively. Upon photolysis, the (4‐isoprenyl‐Cp) 2 ZrCl 2 and ‐HfCl 2 complexes 7a , 8a underwent rapid intramolecular [4+4] cycloaddition reactions to yield the cyclooctadienylene‐bridged ansa ‐metallocenes 9a , 10a in high yields.