Premium
Configurational and Constitutional Dynamics of Enamine Molecular Switches
Author(s) -
Ren Yansong,
Kravchenko Oleksandr,
Ramström Olof
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202003478
Subject(s) - enamine , chemistry , deprotonation , protonation , intramolecular force , isomerization , computational chemistry , derivative (finance) , stereochemistry , organic chemistry , catalysis , ion , financial economics , economics
Dual configurational and constitutional dynamics in systems based on enamine molecular switches has been systematically studied. pH‐responsive moieties, such as 2‐pyridyl and 2‐quinolinyl units, were required on the „stator“ part, also providing enamine stability through intramolecular hydrogen‐bonding (IMHB) effects. Upon protonation or deprotonation, forward and backward switching could be rapidly achieved. Extension of the stator π‐system in the 2‐quinolinyl derivative provided a higher E ‐isomeric equilibrium ratio under neutral conditions, pointing to a means to achieve quantitative forward/backward isomerization processes. The „rotor“ part of the enamine switches exhibited constitutional exchange ability with primary amines. Interestingly, considerably higher exchange rates were observed with amines containing ester groups, indicating potential stabilization of the transition state through IMHB. Acids, particularly Bi III , were found to efficiently catalyze the constitutional dynamic processes. In contrast, the enamine and the formed dynamic enamine system showed excellent stability under basic conditions. This coupled configurational and constitutional dynamics expands the scope of dynamic C−C and C−N bonds and potentiates further studies and applications in the fields of molecular machinery and systems chemistry.