Synthesis, stereochemistry, and photochemical and thermal behaviour of bis-tert-butyl substituted overcrowded alkenes.
In order to study the structural limits in the design of molecular motors, a tert-butyl substituted analogue was prepared. The unexpected photochemical and thermal isomerisation processes and the stereochemistry of new overcrowded alkene are described. The bis tert-butyl substituted alkenes were synthesised in a five-step sequence with an overall yield of 7.5%. Structural assignments of the isomers based on experimental data were supported by calculations of all four isomers of the alkene. X-Ray crystal analysis showed a strongly twisted alkene (torsion angle 39 degrees ) for a less stable photochemically generated cis-isomer.
Ter Wiel
Matthijs K J
MK
Department of Organic and Molecular Inorganic Chemistry, Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Kwit
Marcin G
MG
Meetsma
Auke
A
Feringa
Ben L
BL