Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Application In Synthesis of (1S,2S)-(-)-1,2-Diphenylethylenediamine, you can also check out more blogs about29841-69-8
Chemistry is traditionally divided into organic and inorganic chemistry. Application In Synthesis of (1S,2S)-(-)-1,2-Diphenylethylenediamine. The former is the study of compounds containing at least one carbon-hydrogen bonds.In a patent,Which mentioned a new discovery about 29841-69-8
The relationship between catalyst structure and enantioselectivity in the asymmetric epoxidation of unfunctionalized olefins by a series of chiral Mn(salen) complexes (1-10) was examined.The X-ray structures of 5-coordinate complexes 5, 8, of 6-coordinate 9 (<6,6' = -tBu; 4,4' = -tBu>+ClO4-), and 10 (6,6′ = -tBu; 4,4′ = -Br) were determined.Catalysts 1-9 were derived from (R,R)-1,2-diaminocyclohexane and catalysts 10 from (S,S)-1,2-diphenylethylenediamine.Catalysts 1-9 differ in the stereoelectronic substitution of the ortho (6,6′) and para (4,4′) positions of the salicylidene moiety.A comparison between structures 5, 8, and 9 reveals that the ligand geometry around the metal cnter and the chiral diimine backbone remains remarkably constant in both five- and six-coordinate cyclohexanediamine-derived complexes; in contrast, the salicylidene regions of the complexes display a wide range of conformations.The asymmetric epoxidation of indene and 6-cyano-2,2-dimethylchromene with NaOCl catalyzed by complexes 1-10 was effected.Systematically increasing the steric bulk on the ortho and then the para position in the order 1 (6,6′ = -H; 4,4′ = -H), 2 (6,6′ = -CH3; 4,4′ = -CH3), 3 (6,6′ = -tBu; 4,4′ = -H), 4 (6,6′ = -tBu; 4,4′ = -CH3), 5 (6,6′ = -tBu; 4,4′ = -tBu), and 6 (6,6′ = -tBu; 4,4′ = -trityl), and electronically modifying the para substituents in 7 (6,6′ = -tBu; 4,4′ = -OMe) and 8 (6,6′ = -tBu; 4,4′ = -OTIPS) resulted in enhanced enantioselectivities of the desired epoxides.The conformational variations observed in the solid state are likely to reflect accessible solution conformations and may help explain the high levels of stereoinduction obtained with these catalysts in the asymmetric epoxidation of unfunctionalized olefins. – Keywords: asymmetric epoxidations; catalysis; manganese complexes; structure elucidation
Note that a catalyst decreases the activation energy for both the forward and the reverse reactions and hence accelerates both the forward and the reverse reactions.Application In Synthesis of (1S,2S)-(-)-1,2-Diphenylethylenediamine, you can also check out more blogs about29841-69-8
Reference:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI