Synthesis of furanoid terpenes via an efficient palladium-catalyzed cyclization of 4,6-dienols
摘要:
The total syntheses of marmelo oxides A and B and a terpene alcohol found in peppermint oil are described. The key steps in these syntheses are the regioselective palladium-catalyzed allylic substitution of 4 and 11 to 6a and 12, respectively, and the regioselective palladium-catalyzed cyclization of 8 and 14 to 9a, 9b, and 15, respectively. The relative stereochemistry of marmelo oxides A and B was established by NOE measurements.
DOI:
10.1021/jo00018a027
作为产物:
描述:
alkaline earth salt of/the/ methylsulfuric acid 在
甲醇 、 palladium on activated charcoal 作用下,
生成 3-methyl-1,4-pentadien-3-ol
参考文献:
名称:
Cheeseman et al., Journal of the Chemical Society, 1949, p. 2034
Enantioselective syntheses of tremulenediol A and tremulenolide A
作者:Brandon L. Ashfeld、Stephen F. Martin
DOI:10.1016/j.tet.2006.05.087
日期:2006.11
A and tremulenolide A. The approach features a series of efficient transition metal-catalyzed reactions commencing with an enantioselective rhodium(II)-catalyzed intramolecular cyclopropanation followed by a regioselective allylic alkylation and a diastereoselective rhodium(I)-catalyzed [5+2] cycloaddition.
synthesis of new core-Au/shell-CeO2 nanoparticles (Au@CeO2) using a redox-coprecipitation method, where the Au nanoparticles and the nanoporous shell of CeO2 are simultaneously formed in one step. The Au@CeO2catalyst enables the highly selective semihydrogenation of various alkynes at ambient temperature under additive-free conditions. The core-shellstructure plays a crucial role in providing the excellent
我们报告了一种使用氧化还原共沉淀法轻松合成新的核-Au/壳-CeO2 纳米颗粒(Au@CeO2),其中 Au 纳米颗粒和 CeO2 的纳米多孔壳在一个步骤中同时形成。Au@CeO2 催化剂能够在无添加剂的条件下在环境温度下实现各种炔烃的高选择性半氢化。核-壳结构通过最大化核-Au 和壳-CeO2 之间的界面位点,以异裂方式选择性解离 H2,从而为烯烃提供优异的选择性。
Piperazine-promoted gold-catalyzed hydrogenation: the influence of capping ligands
作者:Jhonatan L. Fiorio、Eduardo C. M. Barbosa、Danielle K. Kikuchi、Pedro H. C. Camargo、Matthias Rudolph、A. Stephen K. Hashmi、Liane M. Rossi
DOI:10.1039/c9cy02016k
日期:——
Goldnanoparticles (NPs) combined with Lewis bases, such as piperazine, were found to perform selective hydrogenation reactions via the heterolytic cleavage of H2. Since goldnanoparticles can be prepared by many different methodologies and using different capping ligands, in this study, we investigated the influence of capping ligands adsorbed on gold surfaces on the formation of the gold–ligand interface
Studies towards Simalikalactone D and Quassimarin: Construction of an Advanced Pentacyclic Intermediate
作者:Tony K. M. Shing、Xue Y. Zhu、Yeung Y. Yeung
DOI:10.1002/chem.200305158
日期:2003.11.21
target molecules simalikalactone D and quassimarin, has been synthesized from (S)-(+)-carvone in 21 steps and with an overall yield of 12 %. The synthesis is efficient, stereocontrolled, enantiospecific, and chirality productive, creating eight new chiral centres in pentacycle, and should provide opportunities for rapid access to simalikalactone D analogues and other bioactive quassinoids. The reaction
Gold–Ligand-Catalyzed Selective Hydrogenation of Alkynes into <i>cis</i>-Alkenes via H<sub>2</sub> Heterolytic Activation by Frustrated Lewis Pairs
作者:Jhonatan L. Fiorio、Núria López、Liane M. Rossi
DOI:10.1021/acscatal.6b03441
日期:2017.4.7
The selective hydrogenation of alkynes to alkenes is an important synthetic process in the chemical industry. It is commonly accomplished using palladium catalysts that contain surface modifiers, such as lead and silver. Here we report that the adsorption of nitrogen-containing bases on gold nanoparticles results in a frustratedLewispair interface that activates H2 heterolytically, allowing an unexpectedly