TY - JOUR
T1 - Synthesis, structure and conformational mobility of tetra-substituted cyanomethoxy: P-tert -butylcalix[4]arenes
AU - D'Alessio, D.
AU - Krause-Heuer, A.M.
AU - Skelton, Brian W.
AU - Fraser, B.H.
AU - Massi, M.
AU - Ogden, Mark I.
PY - 2016
Y1 - 2016
N2 - © The Royal Society of Chemistry 2016.The syntheses and single crystal X-ray structure determinations of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(cyanomethoxy)calix[4]arene (partial-cone conformer), 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-bis(cyanomethoxy)calix[4]arene (cone and partial-cone conformers), 5,11,17,23-tetra-tert-butyl-25,26,27-tris(cyanomethoxy)-28-hydroxycalix[4]arene, and 5,11,17,23-tetra-tert-butyl-25-diethylcarbamoylmethoxy-26,27,28-tris(cyanomethoxy)calix[4]arene (cone conformer) are reported. The calixarenes are found to be conformationally mobile when heated in DMSO, favouring the partial-cone conformer at equilibrium. The tris-substituted cyanomethoxy derivative was found to assume the partial-cone conformation in the solid state. Attempts to convert nitrile groups to tetrazole moieties in derivatives containing both amide and nitrile groups were unsuccessful.
AB - © The Royal Society of Chemistry 2016.The syntheses and single crystal X-ray structure determinations of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(cyanomethoxy)calix[4]arene (partial-cone conformer), 5,11,17,23-tetra-tert-butyl-25,27-bis(diethylcarbamoylmethoxy)-26,28-bis(cyanomethoxy)calix[4]arene (cone and partial-cone conformers), 5,11,17,23-tetra-tert-butyl-25,26,27-tris(cyanomethoxy)-28-hydroxycalix[4]arene, and 5,11,17,23-tetra-tert-butyl-25-diethylcarbamoylmethoxy-26,27,28-tris(cyanomethoxy)calix[4]arene (cone conformer) are reported. The calixarenes are found to be conformationally mobile when heated in DMSO, favouring the partial-cone conformer at equilibrium. The tris-substituted cyanomethoxy derivative was found to assume the partial-cone conformation in the solid state. Attempts to convert nitrile groups to tetrazole moieties in derivatives containing both amide and nitrile groups were unsuccessful.
U2 - 10.1039/c6ra05865e
DO - 10.1039/c6ra05865e
M3 - Article
SN - 2046-2069
VL - 6
SP - 37006
EP - 37011
JO - RSC Advances
JF - RSC Advances
IS - 43
ER -