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Synthesis of Alkyne Metathesis Catalysts from Tris(dimethylamido)tungsten Precursors
Author(s) -
Melcher Daniel,
Àrias Òscar,
Freytag Matthias,
Jones Peter G.,
Tamm Matthias
Publication year - 2020
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.202000835
Subject(s) - chemistry , metathesis , alkoxide , bimetallic strip , tris , ligand (biochemistry) , medicinal chemistry , salt metathesis reaction , tungsten , amide , catalysis , polymer chemistry , organic chemistry , polymerization , biochemistry , polymer , receptor
Benzylidyne tungsten systems bearing a combination of alkoxide and amide ligands were readily obtained by partial alcoholysis of amido‐supported tungsten complexes. Benzylidyne tris(dimethylamido)tungsten was treated with fluorinated alcohols Me 2 (CF 3 )COH, Me(CF 3 ) 2 COH, and (CF 3 ) 3 COH, and also with silanols ( t BuO) 3 SiOH, and Ph 3 SiOH, all of which resulted in complexes of the type [PhC≡W(NHMe 2 )(NMe 2 )(OR) 2 ]. Full displacement of the amido ligands was also achieved in [PhC≡W(NHMe 2 ){OC(CF 3 ) 2 Me}{OSi(O‐ t Bu) 3 } 2 ] and [PhC≡W(NHMe 2 )(OSiPh 3 ) 3 ]. In addition, reaction of the three fluorinated alcohols with hexakis(dimethylamido)ditungsten yielded isomeric mixtures of bimetallic complexes [W 2 (NMe 2 ) 4 (OR) 2 ], which bear two electron‐donating ligands and one electron‐withdrawing ligand per tungsten atom. All amido‐substituted compounds are active in the self‐metathesis of 5‐benzyloxy‐2‐pentyne, although [W 2 (OR) 2 (NMe 2 ) 4 ] complexes require longer initiation times depending on the degree of fluorination of the tert ‐butoxide ligand.