Enantioselective Synthesis of (+)-Estrone Exploiting a Hydrogen Bond-Promoted Diels−Alder Reaction
作者:Marko Weimar、Gerd Dürner、Jan W. Bats、Michael W. Göbel
DOI:10.1021/jo100053j
日期:2010.4.16
Starting from Dane’s diene and methylcyclopentenedione, (+)-estrone is synthesized along the Quinkert−Dane route in 24% total yield. The keystep is an enantioselective Diels−Alderreaction promoted by an amidiniumcatalyst as efficiently as by a traditional Ti-TADDOLate Lewis acid.
从 Dane 的二烯和甲基环戊烯二酮开始,沿 Quinkert-Dane 路线合成 (+)-雌酮,总产率为 24%。关键步骤是由脒催化剂与传统的 Ti-TADDOLate Lewis 酸一样有效地促进对映选择性 Diels-Alder 反应。
Arylisoquinoline-derived organoboron dyes with a triaryl skeleton show dual fluorescence
作者:Vânia F Pais、Tristan Neumann、Ignacio Vayá、M Consuelo Jiménez、Abel Ros、Uwe Pischel
DOI:10.3762/bjoc.15.254
日期:——
synthesized by Suzuki couplings and then transformed into boronic acid esters by employing an Ir(I)-catalyzed reaction. The chromophores show dual emission behavior, where the long-wavelength emission band can reach maxima close to 600 nm in polar solvents. The fluorescence quantum yields of the dyes are generally in the range of 0.2–0.4, reaching in some cases values as high as 0.5–0.6. Laser-flash photolysis