Half-Sandwich Ruthenium Carbene Complexes Link<i>trans</i>-Hydrogenation and<i>gem</i>-Hydrogenation of Internal Alkynes
作者:Alexandre Guthertz、Markus Leutzsch、Lawrence M. Wolf、Puneet Gupta、Stephan M. Rummelt、Richard Goddard、Christophe Farès、Walter Thiel、Alois Fürstner
DOI:10.1021/jacs.8b00665
日期:2018.2.28
E-alkenes are formed by trans-delivery of the two H atoms of H2. A combinedexperimental and computational study now provides a comprehensive mechanistic picture: a metallacyclopropene (η2-vinyl complex) is primarily formed, which either evolves into the E-alkene via a concerted process or reacts to give a half-sandwich ruthenium carbene; in this case, one of the C atoms of the starting alkyne is converted
Enantioselective Epoxidation of Nonconjugated <i>cis</i>-Olefins by Chiral Dioxirane
作者:Christopher P. Burke、Yian Shi
DOI:10.1021/ol901724v
日期:2009.11.19
A variety of nonconjugated cis-olefins has been enantioselectively epoxidized with chiral ketones 2, and up to 92% ee has been obtained. The two prochiral faces of an olefin are likely stereodifferentiated by the relative hydrophobicity of the olefin substituents and/or allylic oxygen functionality.
Stereoselective Synthesis of Tertiary Ethers through Geometric Control of Highly Substituted Oxocarbenium Ions
作者:Lei Liu、Paul E. Floreancig
DOI:10.1002/anie.201002281
日期:2010.8.9
Fully substituted, fully controlled! The geometries of 1,1‐disubstituted oxocarbeniumions and the conformations of oxocarbeniumions that contain a tertiary stereocenter can be predicted based on simple models. These models have been applied to highlystereoselective syntheses of tetrahydropyran derivatives that contain tertiaryethers (see scheme; RL, RS, and RN represent large, small, and nucleophilic
全面换人,全面控制!1,1-二取代的氧碳鎓离子的几何形状和包含叔立构中心的氧碳鎓离子的构象可以基于简单的模型来预测。这些模型已应用于含有叔醚的四氢吡喃衍生物的高度立体选择性合成(参见方案;R L、RS和 R N分别代表大基团、小基团和亲核基团)。
Martin, Annales de Chimie (Cachan, France), 1959, vol. <13>1, p. 541,561
作者:Martin
DOI:——
日期:——
Oxidation of alkynes into conjugated acetylenic ketones with tert-butyl hydroperoxide catalyzed by chromiumVI oxide