Premium
Heteroleptic Alkyl and Amide Iminoanilide Alkaline Earth and Divalent Rare Earth Complexes for the Catalysis of Hydrophosphination and (Cyclo)Hydroamination Reactions
Author(s) -
Liu Bo,
Roisnel Thierry,
Carpentier JeanFrançois,
Sarazin Yann
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201301464
Subject(s) - hydroamination , chemistry , catalysis , ionic radius , amide , alkyl , medicinal chemistry , ligand (biochemistry) , styrene , alkaline earth metal , polymer chemistry , metal , organic chemistry , ion , polymer , biochemistry , receptor , copolymer
[{N^N}M(X)(thf) n ] alkyl (X=CH(SiMe 3 ) 2 ) and amide (X=N(SiMe 3 ) 2 ) complexes of alkaline earths (M=Ca, Sr, Ba) and divalent rare earths (Yb II and Eu II ) bearing an iminoanilide ligand ({N^N} − ) are presented. Remarkably, these complexes proved to be kinetically stable in solution. X‐ray diffraction studies allowed us to establish size–structure trends. Except for one case of oxidation with [{N^N}Yb II {N(SiMe 3 ) 2 }(thf)], all these complexes are stable under the catalytic conditions and constitute effective precatalysts for the cyclohydroamination of terminal aminoalkenes and the intermolecular hydroamination and intermolecular hydrophosphination of activated alkenes. Metals with equal sizes across alkaline earth and rare earth families display almost identical apparent catalytic activity and selectivity. Hydrocarbyl complexes are much better catalyst precursors than their amido analogues. In the case of cyclohydroamination, the apparent activity decreases with metal size: Ca>Sr>Ba, and the kinetic rate law agrees with R CHA = k [precatalyst] 1 [aminoalkene] 1 . The intermolecular hydroamination and hydrophosphination of styrene are anti‐Markovnikov regiospecific. In both cases, the apparent activity increases with the ionic radius (Ca