Darstellung, Eigenschaften und Molekülstrukturen von Alkylaluminiumaminoalkoxidchloriden

Dual Catalyst System for Asymmetric Alternating Copolymerization of Carbon Dioxide and Cyclohexene Oxide with Chiral Aluminum Complexes: Lewis Base as Catalyst Activator and Lewis Acid as Monomer Activator

“…Each reaction of 1a H 2 – 1f H 2 , 2a H 2 – 2i H 2 , or 3 H, with trimethylaluminum (Me 3 Al) was followed by 1 H NMR spectroscopy; the signals assignable to the phenol (at 13–15 ppm for 1a H 2 – 1f H 2 ), enol (at 10–12 ppm for 2a H 2 – 2i H 2 ), or alcohol (at 4.6 ppm for 3 H) disappeared, whereas novel signals assignable to methyl groups vertically connected to the aluminums (Al–Me) appeared at −2 to −1 ppm. These results indicated the formation of the aluminum complexes ( 1a AlMe– 1f AlMe, , [ 2a AlMe] 2 –[ 2i AlMe] 2 , and 3 2 AlMe).…”

“…Three series of optically active aluminum complexes, aluminum chiral Schiff base complexes ( 1a AlMe– 1f AlMe), , aluminum chiral β-ketoiminato complexes ([ 2a AlMe] 2 –[ 2i AlMe] 2 ), and aluminum prolinol complex ( 3 2 AlMe) were synthesized according to Schemes , , and , respectively. (1 R ,2 R )-1,2-Diphenyl-1,2-ethanediamine and (1 R ,2 R )-1,2-cyclohexanediamine were obtained by optical resolutions of the rac -diamines with l -tartaric acid and the subsequent removal of l -tartaric acid with potassium carbonate.…”

“…In the crystal, the aluminum bisprolinol complex 3 2 AlMe formed a five-coordinate, C 2 -symmetric structure similar to the reported literature (Figures and S1 and Table S2 in the Supporting Information). The complex 3 2 AlMe had two regions: one region is “inside walls” enclosed by two phenyl and two pyrroridyl groups as “wall” and the other is “outside walls” surrounded by two remaining phenyl groups alone. Since phenyl groups and pyrroridyl groups in the complex 3 2 AlMe are denoted as “wall” to regulate the direction of CHO approaching the aluminum, the spatial region encircled by “walls” (two phenyl and two pyrroridyl groups) are abbreviated as “inside walls” and the opposite region of “inside walls” against the coordination plane formed by one aluminum and two [N,O] chelating units are named as “outside walls”.…”

“…Following materials were commercially obtained: 2,4-pentanedione, 1,3-diphenyl-1,3-propanedione, tert -butanol, pyridine, N -MeIm, DMAP, 2-picoline, CHO, COO (from TCI); Me 3 Al, Et 4 NOAc (from Aldrich). Following materials were synthesized according to the reported literatures: salen-type Schiff bases [(1 R ,2 R )- N , N ′-bissalicylidene-1,2-diphenylethane-1,2-diamine ( 1a H 2 ), (1 R ,2 R )- N , N ′-bis(3-phenylsalicylidene)-1,2-diphenylethane-1,2-diamine ( 1b H 2 ), (1 R ,2 R )- N , N ′-bis(3,5-di- tert -butylsalicylidene)-1,2-diphenylethane-1,2-diamine ( 1c H 2 ), (1 R ,2 R )- N , N ′-bissalicylidene-1,2-cyclohexanediamine ( 1d H 2 ), (1 R ,2 R )- N , N ′-bis(3-phenylsalicylidene)-1,2-cyclohexanediamine ( 1e H 2 ), and (1 R ,2 R )- N , N ′-bis(3,5-di- tert -butylsalicylidene)-1,2-cyclohexanediamine ( 1f H 2 )], amino alcohols [( S )-2-amino-1-propanol, ( S )-2-amino-3-methyl-1-butanol, ( S )-2-amino-4-methyl-1-pentanol, (2 S ,3 S )-2-amino-3-methyl-1-pentanol, ( S )-2-amino-3-phenyl-1-propanol, ( S )-2-amino-2-phenylethanol, and ( R )-2-amino-2-phenylethanol], β-ketoimines [4-(2-hydroxyethylimino)pent-2-en-2-ol ( 2a H 2 ) and 4-(( S )-1-hydroxypropan-2-ylimino)pent-2-en-2-ol ( 2b H 2 )], ( S )-diphenyl(pyrrolidine-2-yl)methanol ( 3 H), aluminum complexes [ 1c AlMe, 1d AlMe, 1f AlMe, [ 2a AlMe] 2 , 3 2 AlMe, and 4 AlMe], bis- N -MeIm, bis- N -MeBzIm, MAD, and CPO …”

“…To our knowledge, chiral aluminum complexes for asymmetric copolymerization of CO 2 and meso -epoxides have never been reported. The complexes used in this study were the aluminum salen-type Schiff base complexes ( 1a AlMe– 1f AlMe), , aluminum β-ketoiminate complexes ([ 2a AlMe] 2 –[ 2i AlMe] 2 ), and aluminum aminoalkoxide complex ( 3 2 AlMe), (Figure ). The details will be described hereinafter.…”