494775-04-1Relevant academic research and scientific papers
Memory of chirality generated by spontaneous crystallization and asymmetric synthesis using the frozen chirality
Sakamoto, Masami,Iwamoto, Takuya,Nono, Naoyuki,Ando, Masaru,Arai, Wataru,Mino, Takashi,Fujita, Tsutomu
, p. 942 - 946 (2003)
Asymmetric synthesis using frozen chirality generated by spontaneous crystallization was performed. Achiral asymmetrically substituted imide with a tetrahydronaphthyl group on the nitrogen atom crystallized in a chiral fashion, with space group P212121. The molecular chirality generated by spontaneous crystallization was retained in cold THF. The half-life determined on the basis of decreasing optical activity followed by CD spectrometer was 7.8, 33.1, and 150.0 min at -20, -30, -40 °C, respectively. The energy barrier (ΔG?) of racemization was calculated with the temperature dependence of the kinetic constant to be 18.24-18.36 kcal mol-1 at 233-253 K. The memorized frozen chirality was transferred to permanent optically active alcohols by nucleophilic addition with n-buthyllithium.
