Synthesis of Single and Double Dibenzohelicenes by Rhodium‐Catalyzed Intramolecular [2+2+2] and [2+1+2+1] Cycloaddition
作者:Ryota Yamano、Yu Shibata、Ken Tanaka
DOI:10.1002/chem.201706008
日期:2018.4.25
Dibenzo[7]helicenes were synthesized with up to 99 % ee by rhodium(I)/binap‐catalyzed enantioselective intramolecular [2+2+2] cycloaddition of 2‐phenylnaphthalene‐linked triynes. Additionally, [2+1+2+1] cycloaddition products, that is, twisted anthracenes, were also synthesized by using difluorphos as ligand. Although these compounds are not configurationally stable at elevated temperature, their Scholl
铑(I)/ binap催化的2-苯基萘连接的三炔对映选择性分子内[2 + 2 + 2]环加成反应合成了高达99%ee的二苯并[7]螺旋酮。另外,还通过使用二氟膦作为配体合成了[2 + 1 + 2 + 1]个环加成产物,即扭曲的蒽。尽管这些化合物在高温下构型不稳定,但它们的Scholl反应可提供构型稳定的双二苯并[6]螺旋。如此获得的二苯并[7] hel烯具有良好的圆偏振发光性能,而双二苯并[6] hel烯具有较高的荧光量子产率。