Palladium-Catalyzed Asymmetric Ring Expansion of Allenylcyclobutanols: An Asymmetric Wagner−Meerwein Shift
作者:Barry M. Trost、Jia Xie
DOI:10.1021/ja0602501
日期:2006.5.1
In this study, we developed a palladium-catalyzed atom economic asymmetricWagner-Meerweinshift of allenylcyclobutanol substrates. It is an excellent method for creating functionalized cyclopentanones with an alpha-chiral O-tertiary center by ring expansion of allenylcyclobutanols. This reaction was initiated by hydropalladation and afforded excellent enantioselectivity as well as atom economy. This
Controlled Click-Assembly of Well-Defined Hetero-Bifunctional Cubic Silsesquioxanes and Their Application in Targeted Bioimaging
作者:M. Eugenia Pérez-Ojeda、Beatriz Trastoy、Álvaro Rol、María D. Chiara、Inmaculada García-Moreno、Jose Luis Chiara
DOI:10.1002/chem.201300339
日期:2013.5.17
for the controlled assembly of precisely defined hybrid nanomaterials and a fluorescent multivalent probe for application in targeted cell‐imaging. The inorganic cage provides an improved photostability to the covalently attached dye as well as a convenient framework for the 3D multivalent display of the pendant epitopes. Thus, fluorescent bioprobes based on well‐defined cubicsilsesquioxanes offer interesting
Palladium-Catalyzed Diastereo- and Enantioselective Wagner−Meerwein Shift: Control of Absolute Stereochemistry in the C−C Bond Migration Event
作者:Barry M. Trost、Jia Xie
DOI:10.1021/ja7111299
日期:2008.5.1
Inducing absolute stereochemistry in Wagner-Meerwein shifts was examined in a ring expansion protocol. Initiated by generation of a pi-allylpalladium intermediate by hydropalladation of allenes, the ring expansion of allenylcyclobutanol substrates proceeded with excellent diastereo- and enantioselectivities. The results demonstrate that, during the C-C bond migration process, our chiral catalysts can control the stereochemistry of both the pi-allylpalladium intermediate and the corresponding migration bond. Moreover, the stereochemical outcome of the reaction can be rationalized very well with the working model of the chiral catalyst. The method provides an efficient way to synthesize highly substituted cyclopentanones with an alpha-chiral O-tertiary center which has various synthetic applications.
Multigram Synthesis of Heterabicyclo[n.1.0]alkan‐1‐yl Trifluoroborates
作者:Ihor Kleban、Yevhen Krokhmaliuk、Sofiia Reut、Serhii Shuvakin、Vyacheslav V. Pendyukh、Oleksandr I. Khyzhan、Dmytro S. Yarmoliuk、Andriy V. Tymtsunik、Yuliya V. Rassukana、Oleksandr O. Grygorenko
DOI:10.1002/ejoc.202000977
日期:2021.12.21
Multigram synthesis of oxa‐ and azabicyclo[n.1.0]alkan‐1‐yl trifluoroborates relying on efficient 4–5‐step reaction sequences is described. The title compounds was obtained in up to 50 g scale in a single run (10–41 % overall yield).
本文描述了依赖于有效的4-5步反应序列的oxa-和氮杂双环[ n .1.0]烷烃-1-基三氟硼酸酯的合成方法。一次即可获得高达50 g的标题化合物(总收率10–41%)。