Double-Stranded Helical Oligomers Covalently Bridged by Rotary Cyclic Boronate Esters

作者：Iida Hiroki^*; Ohmura Kenji; Noda Ryuta; Iwahana Soichiro; Katagiri Hiroshi; Ousaka Naoki; Hayashi Taku; Hijikata Yuh; Irle Stephan^*; Yashima Eiji^*

来源：Chemistry-An Asian Journal, 2017, 12(8): 927-935.

DOI：10.1002/asia.201700162

• chirality
• double helix
• helical structures
• helix inversion
• molecular rotors

Novel double helices covalently bridged by cyclic boronate esters were synthesized from complementary dimers with an m-terphenyl backbone joined by a chiral or achiral phenylene linker bearing diethyl boronates and diols, respectively. The X-ray crystallographic analysis and variable-temperature NMR and circular dichroism measurements, along with theoretical calculations, revealed that the double helices function as a molecular rotor in which the cyclic boronate ester units rotate, yielding two stable rotamers at low temperatures. Moreover, our data indicates that the covalently bonded double helices can undergo a unique helix-inversion simultaneously with a rotational motion of the boronate esters.

• 出版日期2017-4-18