Ruthenium Carbene Complexes with <i>N</i>,<i>N</i>‘-Bis(mesityl)imidazol-2-ylidene Ligands: RCM Catalysts of Extended Scope
作者:Alois Fürstner、Oliver R. Thiel、Lutz Ackermann、Hans-Jörg Schanz、Steven P. Nolan
DOI:10.1021/jo9918504
日期:2000.4.1
The ruthenium carbene complexes 3a,b bearing imidazol-2-ylidene ligands constitute excellent precatalysts for ring-closing metathesis (RCM) reactions allowing the formation of tri- and tetrasubstituted cycloalkenes. They also apply to annulations that are beyond the scope of the standard Grubbs carbene 1 as well as to ring-closing reactions of acrylic acid derivatives even if the resulting alpha,beta-unsaturated lactones (or lactams) are tri- or tetrasubstituted. The reactivity of 3a was found to be highly dependent on the reaction medium: particularly high reaction rates are observed in toluene, although this solvent also leads to an increased tendency of the catalyst to isomerize the double bonds of the substrates.
Floc'h, Y. Le; Yvergnaux, F.; Toupet, L., Bulletin de la Societe Chimique de France, 1991, # 5, p. 742 - 759
作者:Floc'h, Y. Le、Yvergnaux, F.、Toupet, L.、Gree, R.
DOI:——
日期:——
A short and convergent synthesis of unsaturated macrodilactones