Research interests: Asymmetric catalysis for organic synthesis, including chiral diaminocarbene ligands and VHOIɅDVVHPEOHGGLQXFOHDU catalysts; development of VPDOOPROHFXOHDQWLɅFDQFHU agents; and total synthesis of complex molecules with interesting biological activities. Abstract Novel chiral Co-salen catalysts capable of self-assembly through hydrogen bonding have been developed. First, a self...

In the title complex, [Co(C(22)H(18)N(2)O(4))(CN)(H(2)O)]·CH(3)CN, the Co(III) ion is six-coordinated in a distorted octa-hedral environment defined by two N atoms and two O atoms from a salen ligand in the equatorial plane and one O atom from a water mol-ecule and one C atom from a cyanide group at the axial positions. O-H⋯O hydrogen bonds connect adjacent complex mol-ecules into dimers. C-H⋯N...

electrochemical behavior of the new mono and dinuclear co (iii)  complexes of  the types trans-[pyco((do)(doh)pn )(l)]pf6   and [{py co((do)(doh)pn)}2 (μ-dicyd)] (pf6)2   have been studied in acetonitrile solution.  all the  mono nuclear complexes  show two quasi- reversible reduction couples associate  to co(iii/ii)and  co(ii/i). each of these redox couples split to two  one electron  waves in...

Anion exchange of BF(4)(-) occurs by stirring a cobalt(III) complex of salen-type ligand tethered by four quaternary ammonium BF(4)(-) salts over a slurry of NaX in CH(2)Cl(2), affording a complex containing four X's per cobalt (X = 2,4,5-trichlorophenolate, 6; X = 4-nitrophenolate, 10; X = 2,4-dichlorophenolate, 12). The (1)H and (13)C NMR spectra are in agreement with an unusual imine uncoord...

The mechanism of the hydrolytic kinetic resolution (HKR) of terminal epoxides was investigated by kinetic analysis using reaction calorimetry. The chiral (salen)Co-X complex (X = OAc, OTs, Cl) undergoes irreversible conversion to (salen)Co-OH during the course of the HKR and thus serves as both precatalyst and cocatalyst in a cooperative bimetallic catalytic mechanism. This insight led to the i...

A cobalt salen pentenoate complex [salen=(R,R)-N,N?-bis(3,5-di-tertbutylsalicylidene)-1,2-cyclohexanediamine] is rationally designed as the catalyst for ring-opening copolymerization (ROCOP) of epoxides/anhydrides/CO2. Via migratory insertion carbon monoxide (CO) into Co?O bonds, ROCOP-active species ?-alkene-?-O-CoIII(salen) can be rapidly and quantitatively transformed ?-alkene-?-O2C-CoIII(sa...

Exploiting carbon dioxide as co-monomer with epoxides in the production of polycarbonates is economically highly attractive. More effective catalysts for this reaction are intensively being sought. To promote better understanding of the catalytic pathways, this study uses density functional theory calculations to elucidate the reaction step of CO2 insertion into cobalt(III)-alkoxide bonds, whic...

Three interconnected catalytic cycles account for the title reaction catalyzed by a bimetallic aluminum(salen) complex and Bu(4)NBr. In the first, Bu(4)NBr acts as a nucleophile to activate the epoxide. In the second, Bu(3)N generated in situ serves to activate CO(2). In the third, the aluminum(salen) complex brings the two activated species together so that the key bonds can be formed intramol...

We analyzed the apoptosis and anti-tumour activities of several Mn(III)-salen and -salphen complexes (1-14) towards three different cultured human cancer and non-cancer cells. We demonstrated that most of the Mn(III)-salen and -salphen complexes affect cell viability and induce apoptosis in MCF7 cells. Biochemically active Mn(III)-salen and -salphen complexes induced nuclear fragmentation and r...

1, 8-dioxo-octahydroxanthene derivatives have efficiently been synthesized from dimedone and aromatic aldehydes using [fe(iii)(salen)cl] complex as an efficient and homogeneous catalyst in molten tetrabutyl ammonium bromide. this methodology offers several advantages, such as good yields, short reaction times, simple procedure, and mild conditions.