Asymmetric Cyclopropanation of Styrene Catalyzed by Cu–(Chiral Schiff-Base) Complexes

New copper(I) and silver(I) triazolato-complexes: Synthesis, reactivity and catalytic activity in olefin cyclopropanation

“…Increasing the size of R on N 2 CHCOOR enhances enantiocontrol, while the diastereoselectivity is not usually affected by steric effects, except when very bulky substituents are used, as in the case of 2,6-di-tert-butyl-4-methyl phenyl (BDA) diazoacetate [27]. Also species 1 confirmed this trend, providing a 70:30 trans:cis ratio in the catalytic cyclopropanation of styrene, as reported for other Cu(Schiff-base) catalysts with substituted salicylaldehydes [28]. Unfortunately, a lower trans-diastereoselectivity was observed using a-methylstyrene as substrate (entry 2).…”

Convenient, mild and rapid synthesis and characterization of some Schiff-base ligands and their complexes with uranyl(II) ion

“…Organometallic complexes containing Schiff bases [13] have been used as catalysts for asymmetric cyclopropanation [14][15][16][17] and enantioselective aziridination [18]. Recently, bisbidentate Schiff-base metal complexes have been used as polymerization catalysts [19], in molecular hyperpolarizability studies [20] and for preparation of ion selective electrodes [21][22][23][24][25].…”

2,2′-(Propane-1,3-diyldioxy)dibenzaldehyde

“…Much attention has been paid to the synthesis, coordination chemistry and catalytic application of salicylaldehyde, its Schiff bases and metal complexes (Hata et al, 2004;Scherhag & Spicer, 2000;Mukherjee et al, 2001;Li et al, 2000), leading to the characterization of many derivatives. Meanwhile, interactions, such as C-HÁ Á Á,and weak hydrogenbonding interactions (C-HÁ Á ÁX: X = O, N, Cl, Br), are known to play crucial roles in molecular self-assembly and crystal symmetry in biology, chemistry and materials science (Leininger et al, 2000;Mü ller-Dethlefs & Hobza, 2000;Conn & Rebek, 1997;Hunter et al, 1991;Desiraju, 2005).…”