Trans-2-(1,2,3-triazolyl)-cyclohexanols as Potential pHTriggered Molecular Switches
Poster Number
22
Format
Poster Presentation
Faculty Mentor Name
Vyacheslav Samoshin
Faculty Mentor Department
Chemistry
Abstract/Artist Statement
Conformational molecular switches are molecular systems that reversibly change the relative orientation of their parts under external stimulus. They play a central role in the design of molecular machinery, controllable compounds and intelligent materials for possible use in many applications, including drug release, new sensor techniques or information storage and transmission. In particular, the trans-2- aminocyclohexanol moiety was used to construct the conformationally controlled crown-ethers and podands, and the pH-sensitive components of liposomes for targeted drug delivery. To further expand the variety of potential pHtriggers, we explored a new type of conformational switch based on trans-2-(1,2,3- triazolyl)-cyclohexanol. A series of these compounds was synthesized by a “click-reaction” of bis-ethoxycarbonyl-trans-2- azidocyclohexanol with substituted alkynes. This approach allows a broad variation of target structures. Select triazolyl compounds were also synthesized with various blocking groups on oxygen to limit premature hydrogen bonding before pH change. The conformational equilibrium and its pH-induced change were studied by 1H-NMR in several solvents. The position of equilibrium depends on the substituents at triazolyl cycle and on the solvent. However, the desired pH-sensitivity is limited by the initial bias of equilibrium towards the conformer with diequatorial triazolyl and oxy groups.
Location
DeRosa University Center, Ballroom
Start Date
25-4-2015 10:00 AM
End Date
25-4-2015 12:00 PM
Trans-2-(1,2,3-triazolyl)-cyclohexanols as Potential pHTriggered Molecular Switches
DeRosa University Center, Ballroom
Conformational molecular switches are molecular systems that reversibly change the relative orientation of their parts under external stimulus. They play a central role in the design of molecular machinery, controllable compounds and intelligent materials for possible use in many applications, including drug release, new sensor techniques or information storage and transmission. In particular, the trans-2- aminocyclohexanol moiety was used to construct the conformationally controlled crown-ethers and podands, and the pH-sensitive components of liposomes for targeted drug delivery. To further expand the variety of potential pHtriggers, we explored a new type of conformational switch based on trans-2-(1,2,3- triazolyl)-cyclohexanol. A series of these compounds was synthesized by a “click-reaction” of bis-ethoxycarbonyl-trans-2- azidocyclohexanol with substituted alkynes. This approach allows a broad variation of target structures. Select triazolyl compounds were also synthesized with various blocking groups on oxygen to limit premature hydrogen bonding before pH change. The conformational equilibrium and its pH-induced change were studied by 1H-NMR in several solvents. The position of equilibrium depends on the substituents at triazolyl cycle and on the solvent. However, the desired pH-sensitivity is limited by the initial bias of equilibrium towards the conformer with diequatorial triazolyl and oxy groups.