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Synthesis and Coordination Chemistry of Chelate Ligands Containing Cyclopentadienyl, Indenyl and Fluorenyl Donors − Diastereoselectivity and NMR Structure Analysis
Author(s) -
Vogelgesang Joachim,
Frick Axel,
Huttner Gottfried,
Kircher Peter
Publication year - 2001
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 - 10.1002/1099-0682(200104)2001:4<949::aid-ejic949>3.0.co;2-#
Subject(s) - chemistry , cyclopentadienyl complex , coordination complex , chelation , nuclear magnetic resonance spectroscopy , polymer chemistry , stereochemistry , inorganic chemistry , organic chemistry , catalysis , metal
The functionalised oxetane O(CH 2 ) 2 C(CH 2 Br)(CH 2 OMs) ( 1 ) is transformed into tripod ligands ROCH 2 C(CH 2 PPh 2 )(CH 2 PR′ 2 )(CH 2 Cp # ) (R = H, SiMe 3 ; R′ = Ph, Et; Cp # = indenyl, fluorenyl) ( 4 ) in a few steps. Epichlorohydrin O(CH 2 )CH(CH 2 Cl) ( 5 ) allows for diastereoselective one‐pot syntheses of the Cp‐functionalised chelate ligands (Cp # CH 2 )C(H)OH(CH 2 PPh 2 ) (Cp # = Cp, indenyl, fluorenyl) ( 6 ). The SiMe 3 ‐protected derivatives of these ligands react with RuCl 2 (PPh 3 ) 3 to produce {Me 3 SiOCH(CH 2 ‐η 1 ‐PPh 2 )(CH 2 ‐η 5 ‐Cp # )Ru(PPh 3 )(Cl)} (Cp # = Cp, indenyl) ( 15 ) with high diastereoselective preference. With the same starting material, tripod ligands 4 form Me 3 SiOCH 2 C(CH 2 ‐η 1 ‐PPh 2 )(CH 2 ‐η 1 ‐PR 2 )(CH 2 ‐η 5 ‐Indenyl)RuCl (R = Ph, Et) ( 16 ). As shown by complete NMR spectroscopy based structure analyses (DG methods) of 16 , the formation of 16 (R = Et) is diastereoselective. The only diastereomer which is observed is the one in which the PEt 2 donor and the phenylene part of the indenyl ligand are juxtaposed. In addition to quantitative NMR spectroscopy structure analyses, traditional analytical techniques, including X‐ray analyses, were used to confirm the results.