Designed Bifunctional Phosphine Ligand-Enabled Gold-Catalyzed Isomerizations of Ynamides and Allenamides: Stereoselective and Regioselective Formation of 1-Amido-1,3-dienes
摘要:
By using designed biphenyl-2-ylphosphines functionalized with a remote basic groups as ligands, N-alkynyl-o-nosylamides are directly converted to (1E,3E)-1-amido-1,3-dienes with excellent diastereoselectivities under gold catalysis. With allenamides as substrates, the gold-catalyzed isomerizations are high yielding and applicable to a broad substrate scope including various nitrogen protecting groups and exhibit unprecedented (3E)-selectivities for the distal C-C double bond and good regioselectivities. Combining this gold catalysis with one-pot Diels-Alder reactions leads to rapid assembly of valuable bicyclic compounds.
Comparative phytotoxicity of four monoterpenes against Cassia occidentalis
摘要:
SummaryThe effect of four monoterpenes ‐ citronellol, citronellal, cineole and linalool ‐ on the germination, growth and physiology of Cassia occidentalis was investigated. All four monoterpenes reduced germination of C. occidentalis seeds but to varying extents. Citronellal and linalool completely inhibited germination beyond the concentrations of 55 and 110 μM, respectively, whereas in response to treatment of citronellol no germination was observed beyond 330 μM. Further, the growth of seedlings, measured in terms of seedling length and biomass, was also adversely affected. A reduction in chlorophyll content of the cotyledonary leaves of C. occidentalis was also noticed, indicating an adverse effect on photosynthesis. Likewise, respiratory ability of growing seeds was also impaired in response to all four monoterpenes, clearly indicating that monoterpenes affect energy metabolism. On the basis of overall phytotoxicity, potency of monoterpenes was in the order of citronellal > linalool > citronellol > cineole. The results from this study suggest that both citronellal and linalool possess strong phytotoxic potential and can thus serve as lead molecules for the synthesis of bioherbicides.
Gold(<scp>i</scp>) “click” 1,2,3-triazolylidenes: synthesis, self-assembly and catalysis
作者:Kelly J. Kilpin、Ursula S. D. Paul、Ai-Lan Lee、James D. Crowley
DOI:10.1039/c0cc02185g
日期:——
Novel gold(I) âclickâ carbene(1,2,3-triazolylidene) complexes have been synthesised, characterised and exploited for the self-assembly of a metallomacrocycle and as precatalysts for gold(I)-catalysed reactions.
A dual-functional urea-linked conjugated porous polymer anchoring silver nanoparticles for highly efficient CO<sub>2</sub> conversion under mild conditions
作者:Xiaoji Wang、Wang Li、Jianxin Wang、Jie Zhu、Yuting Li、Xiaozhen Liu、Liping Wang、Lin Li
DOI:10.1039/d0dt02559c
日期:——
cyclization of propargyl alcohols with CO2 under mild conditions, together with good recyclability, which is probably attributed to the synergistic effect of the UCPP on the adsorption and activation of CO2 and the immobilization of Ag nanoparticles. This work affords possible opportunities for the design and synthesis of a heterogeneous catalyst toward CO2 conversion.
The gold standard: A gold‐catalyzed cascadereaction sequence for the preparation of polycyclicfusedindole cores exploits the ready availability and chemical flexibility of propargylic alcohols. The desired tri‐ or tetracyclic compounds are obtained in good yields with water as the only stoichiometric by‐product.
METHOD OF HYDROSILYLATION IMPLEMENTING AN ORGANIC CATALYST DERIVED FROM GERMYLENE
申请人:BLUESTAR SILICONES FRANCE SAS
公开号:US20170313729A1
公开(公告)日:2017-11-02
The present invention concerns a method for the hydrosilylation of an unsaturated compound comprising at least one ketone function, one aldehyde function, one alkene function and/or one alkyne function, with a compound comprising at least one hydrogen-silyl function implementing an organic catalyst of tri-coordinated germanium.