外消旋 4,12-双官能化 [2.2] 对环芳烃合成并通过(循环)HPLC 在半制备规模的固定 CHIRALPAK IA 相上成功解析。它们的绝对构型是通过 X 射线晶体结构分析和/或通过将它们的特定旋光度与文献数据进行比较来确定的。这些是有价值的功能化 C2 对称构件,用于形成更复杂的 V 形手性分子结构,正如一些探索性转化所证明的那样。
外消旋 4,12-双官能化 [2.2] 对环芳烃合成并通过(循环)HPLC 在半制备规模的固定 CHIRALPAK IA 相上成功解析。它们的绝对构型是通过 X 射线晶体结构分析和/或通过将它们的特定旋光度与文献数据进行比较来确定的。这些是有价值的功能化 C2 对称构件,用于形成更复杂的 V 形手性分子结构,正如一些探索性转化所证明的那样。
enhancement in circulardichroism (CD) spectra thanks to the large magnetic/electric transition dipole moments. In the dicationic state, an intramolecular π dimer was formed due to the strong interactions of the oligothiophenes. We further recorded unprecedented wide ranges of CD spectra in 250–1800 nm region. The transitions are reasonably described by the exciton coupling of the oligothiophenes.
Macro rings. XXXVII. Multiple electrophilic substitution reactions of [2.2]paracyclophanes and interconversions of polysubstituted derivatives
作者:Hans J. Reich、Donald J. Cram
DOI:10.1021/ja01041a017
日期:1969.6
Cryst., 18, 958 (1965). (5) (a) W. F. Gorham, Candian Patent 638,335 (1962); (b) Y. L. Yeh, U. S. Patent 3,155,172 (1962); (c) Y. L. Yeh, U. S. Patent 3,349,124 (1967); (d) Y. L. Yeh, Canadian Patent 705,457 (1965); (e) Y. L. Yeh, Canadian Patent 772,189 (1967); (f) Y. L. Yeh, U. S Patent 3,155,712 (1964); (g) W. F. Gorham, U. S. Patent 3,117,168 (1964); (h) Y. L. Yeh and W. F. Gorham, J . Org. Chem.,
active through‐space conjugated oligomers, namely, a dimer, trimer, tetramer, and cyclic trimer, consisting of a planar‐chiral [2.2]paracyclophane skeleton were synthesized. In the ground state, observed similarities in the chiropticalproperties of the oligomers were attributed to the equivalent orientations of two adjacent chromophores. In the excited state, the oligomers were folded into a form analogous
To elucidate the effect of π-conjugation length on chiropticalproperties in circular dichroism (CD) and circularly polarized luminescence (CPL) spectra, stereogenic oligophenylenes containing biph...
Stereogenic cyclic dimers based on 2,2'-biselenophene linked with [2.2]paracyclophane have been synthesized to investigate their chiroptical properties. Embedding selenophene led to the formation of intramolecular Seπ interactions between the two biselenophene strands. The resulting rigid cyclic system exhibits enhanced chiroptical properties when compared with its precursor. In addition, the electrochemical