Asymmetric Total Synthesis of Nigerone andent-Nigerone: Enantioselective Oxidative Biaryl Coupling of Highly Hindered Naphthols
作者:Marisa C. Kozlowski、Elizabeth C. Dugan、Evan S. DiVirgilio、Katja Maksimenka、Gerhard Bringmann
DOI:10.1002/adsc.200600570
日期:2007.3.5
An enantioselective synthesis of the chiral bisnaphthopyrone natural product nigerone and its enantiomer, ent-nigerone, has been realized. The use of constrained 2-naphthol substrates was critical to producing highly functionalized chiral 1,1′-binaphthols via asymmetric oxidative biaryl coupling with 1,5-diaza-cis-decalin copper complexes. The final natural product was formed via a key eight-step isomerization
手性bisnaphthopyrone天然产物nigerone及其对映体,的对映选择性合成ENT -nigerone,已经实现。受限的2-萘酚底物的使用对于通过不对称的氧化联芳基与1,5-二氮杂-顺式十氢化萘铜配合物的偶合生成高度官能化的手性1,1'-联萘酚至关重要。最终的天然产物是通过偶联产物bisisonigerone的关键八步异构化过程形成的,并保留了联芳基构型。通过将圆二色性(CD)测量和量子化学CD计算相结合,确定了双异双酮和尼日尔酮的轴向构型。