A new protocol to obtain 3-substituted 2-cyclohexenones, was developed by reversing the chemical reactivity of 2-cyclohexenone. One-pot synthesis of 3-substituted 2-cyclohexenones can be achieved by treatment of 3-phenylthiosilyl enol ether with a mixture of t-BuLi/HMPA that allows hydrogen-selective exchange in presence of reactive electrophiles such as aldehydes, ketones and alkyl halides. This affords
synthesis of strong boron-centered Lewis superacids. The Lewis superacids were characterized by NMR, XRD and FIA computation. The ferrocenium-substituted boranes were applied in catalytic C−F and S−F bondactivations.
二茂铁取代的硼烷和硼酸酯的氧化可以直接合成以硼为中心的强路易斯超强酸。路易斯超强酸通过 NMR、XRD 和 FIA 计算来表征。二茂铁取代的硼烷用于催化 C-F 和 S-F 键活化。
A Switch of Reactivity Profile in Ionic Intramolecular Annulation Reactions: A Short and Efficient Synthesis of <scp>d</scp>-(+)-Biotin
作者:Subhash P. Chavan、Rajkumar B. Tejwani、T. Ravindranathan
DOI:10.1021/jo015730j
日期:2001.9.1
A Catalytic Synthesis of Thiosilanes and Silthianes: Palladium Nanoparticle-Mediated Cross-Coupling of Silanes with Thio Phenyl and Thio Vinyl Ethers through Selective Carbon−Sulfur Bond Activation
作者:Mee-Kyung Chung、Marcel Schlaf
DOI:10.1021/ja049386u
日期:2004.6.1
Palladium nanoparticles generated in situ from N,N-dimethyl-acetamide (DMA) solutions of PdX2 (X = Cl-, OAc-, OCOCF3-) or Pd-2(dba)(3) by reduction with alkyl silanes R3SiH (R = Me, Et, i-Pr, t-Bu) are selective catalysts for the cross-coupling of the silanes R3SiH with phenyl and vinyl thioethers forming the corresponding thiosilanes and silthianes in high yields and under mild conditions. The method is applicable to phenyl thioglycosides, giving access to thiosilyl glycosides a new class of sugar derivatives.
<i>O</i>-Silylated Ketene Acetal Chemistry<sup>1</sup>; A Mild and Efficient<i>t</i>-Butyldimethylsilylating Agent