摘要
Winding vine-shaped biphenyl derivatives were synthesized through the annulation reaction of nosylated (2-nitrobenzenesulfonyl) ethylenediamine and the E-selective ring-closing metathesis reaction. The structures of the cyclized products were confirmed by measurements of 1 H and 13 C NMR spectra and single crystal X-ray analyses. The obtained cyclic product was revealed to exhibit molecular asymmetry, which was confirmed by HPLC analyses on chiral stationary phase. Compared with our previous results on the related bithiophene derivatives, the obtained vine-shaped biphenyls were shown to hardly racemize under ambient conditions and experimental studies on racemization behaviors suggested energy barriers of 134 kJmol −1 to 211 kJmol −1 . These results reasonably agreed with those of the calculated values based on DFT.