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Reactions of Pentafulvene Complexes of Titanium with Carbonyl Compounds − Diastereoselective Synthesis of σ,π‐Chelate Complexes with Cp~O Ligands
Author(s) -
Stroot Jörg,
Beckhaus Rüdiger,
Saak Wolfgang,
Haase Detlev,
Lützen Arne
Publication year - 2002
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(200207)2002:7<1729::aid-ejic1729>3.0.co;2-k
Subject(s) - chemistry , diastereomer , steric effects , substituent , chelation , medicinal chemistry , stereochemistry , metal , coordination sphere , crystal structure , titanium , crystallography , organic chemistry
The compound Cp*Ti[η 6 ‐C 5 H 4 C(H)( t Bu)]Cl ( 1 ) reacts with ketones, aldehydes, and esters to give σ,π‐chelate complexes with Cp~O ligands through insertion of the carbonyl group into the Ti−C(H)( t Bu) bond. Starting from diastereomerically pure 1 , the reaction with symmetric ketones R 2 CO led to the formation of two diastereomeric products. The diastereomeric ratio could be controlled by steric and electronic properties of the substituent R. Thus, this procedure provides an easy approach to complexes with Cp~O ligands where new chiral centres are formed directly in the coordination sphere of the metal atom through a side‐differentiated attack of the carbonyl compound at the titanium atom. All products were thoroughly characterized. Crystal structure determinations were carried out on 2a , 3a , 5 , 6b , and 9a . (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)