Limits...
Gelation-driven Dynamic Systemic Resolution: in situ Generation and Self-Selection of an Organogelator.

Hu L, Zhang Y, Ramström O - Sci Rep (2015)

Bottom Line: An organogelator was produced and identified from a dynamic imine system, resolved and amplified by selective gelation.The formation of the organogel was monitored in situ by (1)H NMR, showing the existence of multiple reversible reactions operating simultaneously, and the redistribution of the involved species during gelation.The formed organogelator proved effective with a range of organic solvents, including DMSO, toluene, and longer, linear alcohols.

View Article: PubMed Central - PubMed

Affiliation: KTH - Royal Institute of Technology, Department of Chemistry, Teknikringen 30, Stockholm, Sweden.

ABSTRACT
An organogelator was produced and identified from a dynamic imine system, resolved and amplified by selective gelation. The formation of the organogel was monitored in situ by (1)H NMR, showing the existence of multiple reversible reactions operating simultaneously, and the redistribution of the involved species during gelation. The formed organogelator proved effective with a range of organic solvents, including DMSO, toluene, and longer, linear alcohols.

No MeSH data available.


Gelation-driven dynamic systemic resolution of parallel dynamic imine and hemiacetal system.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4462186&req=5

f3: Gelation-driven dynamic systemic resolution of parallel dynamic imine and hemiacetal system.

Mentions: Based on these criteria, four aromatic aldehydes (1–4), representing both five- and six-membered rings, and two amines, either with a carbamate-linked cholesterol core (A) or using a tert-butyloxycarbonyl (Boc) group (B), were selected as components. Prototype dynamic systems were subsequently generated in n-butanol-d10 with each component present in equimolar amount (Fig. 3). The equilibration processes between the aldehydes and each of the amines were examined separately due to the overlap of the product signals (Fig. 4). Imine formation and exchange occurred rapidly, and according to the 1H NMR analyses, both equilibria were attained within one hour. In the system between the aldehydes and amine A, the product ratio between imines 1A, 2A, 3A and 4A was 1:1.6:1.8:2.5 compared to 1:2.1:2.9:9.0 in the equilibrium between the aldehydes and amine B. In the first system, CDCl3 was added (20% v/v) to prevent precipitation, whereas this was unnecessary in the second system. Interestingly, even though the substitution pattern of the aromatic ring of aldehyde 1 involves two very electron-withdrawing nitro groups, the corresponding product 1A was the least preferred compound compared with the other imine products. However, this effect proved to be due to the favored formation of hemiacetal 1C from the addition of deuterated n-butanol to aldehyde 1. In the three parallel reversible reactions, the hemiacetal formation dominated the competition. Small amounts of hemiacetal 3C were also detected in both equilibria, while furfural 2 and imidazole-2-carboxaldehyde 4 showed a tendency to form mainly imine products.


Gelation-driven Dynamic Systemic Resolution: in situ Generation and Self-Selection of an Organogelator.

Hu L, Zhang Y, Ramström O - Sci Rep (2015)

Gelation-driven dynamic systemic resolution of parallel dynamic imine and hemiacetal system.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4462186&req=5

f3: Gelation-driven dynamic systemic resolution of parallel dynamic imine and hemiacetal system.
Mentions: Based on these criteria, four aromatic aldehydes (1–4), representing both five- and six-membered rings, and two amines, either with a carbamate-linked cholesterol core (A) or using a tert-butyloxycarbonyl (Boc) group (B), were selected as components. Prototype dynamic systems were subsequently generated in n-butanol-d10 with each component present in equimolar amount (Fig. 3). The equilibration processes between the aldehydes and each of the amines were examined separately due to the overlap of the product signals (Fig. 4). Imine formation and exchange occurred rapidly, and according to the 1H NMR analyses, both equilibria were attained within one hour. In the system between the aldehydes and amine A, the product ratio between imines 1A, 2A, 3A and 4A was 1:1.6:1.8:2.5 compared to 1:2.1:2.9:9.0 in the equilibrium between the aldehydes and amine B. In the first system, CDCl3 was added (20% v/v) to prevent precipitation, whereas this was unnecessary in the second system. Interestingly, even though the substitution pattern of the aromatic ring of aldehyde 1 involves two very electron-withdrawing nitro groups, the corresponding product 1A was the least preferred compound compared with the other imine products. However, this effect proved to be due to the favored formation of hemiacetal 1C from the addition of deuterated n-butanol to aldehyde 1. In the three parallel reversible reactions, the hemiacetal formation dominated the competition. Small amounts of hemiacetal 3C were also detected in both equilibria, while furfural 2 and imidazole-2-carboxaldehyde 4 showed a tendency to form mainly imine products.

Bottom Line: An organogelator was produced and identified from a dynamic imine system, resolved and amplified by selective gelation.The formation of the organogel was monitored in situ by (1)H NMR, showing the existence of multiple reversible reactions operating simultaneously, and the redistribution of the involved species during gelation.The formed organogelator proved effective with a range of organic solvents, including DMSO, toluene, and longer, linear alcohols.

View Article: PubMed Central - PubMed

Affiliation: KTH - Royal Institute of Technology, Department of Chemistry, Teknikringen 30, Stockholm, Sweden.

ABSTRACT
An organogelator was produced and identified from a dynamic imine system, resolved and amplified by selective gelation. The formation of the organogel was monitored in situ by (1)H NMR, showing the existence of multiple reversible reactions operating simultaneously, and the redistribution of the involved species during gelation. The formed organogelator proved effective with a range of organic solvents, including DMSO, toluene, and longer, linear alcohols.

No MeSH data available.