TY - JOUR
T1 - Synthesis and reactivity of ruthenium phosphite indenylidene complexes
AU - Bantreil, Xavier
AU - Poater, Albert
AU - Urbina-Blanco, César A.
AU - Bidal, Yannick D.
AU - Falivene, Laura
AU - Randall, Rebecca A.M.
AU - Cavallo, Luigi
AU - Slawin, Alexandra M.Z.
AU - Cazin, Catherine S.J.
PY - 2012/11/13
Y1 - 2012/11/13
N2 - The synthesis of the four olefin metathesis precatalysts Caz-1a-d, featuring the NHC ligand N,N′-bis(2,4,6-trimethylphenyl)imidazolin-2- ylidene (SIMes) and four different phosphites (P(O iPr) 3, P(OPh) 3, P(OEt) 3, and P(OMe) 3), is reported. The complexes are readily synthesized from commercially available [RuCl 2(3-phenylinden-1-ylidene)(pyridine)(SIMes)] (Ind-III) in yields of up to 88%. These complexes adopt an unusual cis configuration between the phosphite and the NHC ligands. NMR experiments and computational studies confirm that the cis complexes are thermodynamically favored in comparison to their trans counterparts. In addition, the isomerization from trans to cis occurs via a mononuclear and non-dissociative mechanism. Among the four precatalysts, cis-Caz-1a, featuring a P(O iPr) 3 ligand, displays the highest activity in ring-closing metathesis and cross-metathesis transformations. Experiments at low catalyst loadings demonstrated the potential of this catalyst, allowing better conversions than with commonly used commercially available precatalysts.
AB - The synthesis of the four olefin metathesis precatalysts Caz-1a-d, featuring the NHC ligand N,N′-bis(2,4,6-trimethylphenyl)imidazolin-2- ylidene (SIMes) and four different phosphites (P(O iPr) 3, P(OPh) 3, P(OEt) 3, and P(OMe) 3), is reported. The complexes are readily synthesized from commercially available [RuCl 2(3-phenylinden-1-ylidene)(pyridine)(SIMes)] (Ind-III) in yields of up to 88%. These complexes adopt an unusual cis configuration between the phosphite and the NHC ligands. NMR experiments and computational studies confirm that the cis complexes are thermodynamically favored in comparison to their trans counterparts. In addition, the isomerization from trans to cis occurs via a mononuclear and non-dissociative mechanism. Among the four precatalysts, cis-Caz-1a, featuring a P(O iPr) 3 ligand, displays the highest activity in ring-closing metathesis and cross-metathesis transformations. Experiments at low catalyst loadings demonstrated the potential of this catalyst, allowing better conversions than with commonly used commercially available precatalysts.
UR - http://www.scopus.com/inward/record.url?scp=84869070835&partnerID=8YFLogxK
U2 - 10.1021/om300703p
DO - 10.1021/om300703p
M3 - Article
AN - SCOPUS:84869070835
SN - 0276-7333
VL - 31
SP - 7415
EP - 7426
JO - Organometallics
JF - Organometallics
IS - 21
ER -