Synthesis and properties of calix[4]arene telluropodant ethers as Ag⁺ selective sensors and Ag⁺, Hg²⁺ extractants

• Yang Lu,
• Yuanyuan Li,
• Song He,
• Yan Lu,
• Changying Liu,
• Xianshun Zeng and
• Langxing Chen

Beilstein J. Org. Chem. 2009, 5, No. 59, doi:10.3762/bjoc.5.59

• ]arene 10 and 12. Selectivity coefficients (logK) of the electrodes based on ionophores 6–8, 10 and 12.a The percentage of metal picrates extracted from the aqueous to the organic phase by calixarenes 6–8, 10, and 12. Acknowledgments The Project partially sponsored by SRF for ROCS, SEM, the Natural

Gold film- catalysed benzannulation by Microwave- Assisted, Continuous Flow Organic Synthesis (MACOS)

• Gjergji Shore,
• Michael Tsimerman and
• Michael G. Organ

Beilstein J. Org. Chem. 2009, 5, No. 35, doi:10.3762/bjoc.5.35

• assessment of different types of metal films for their utility in benzannulation. The morphology of Cu, Pd, Ag, and Au films can be compared in the scanning electron microscopy (SEM) images in Figure 2. The films are generally prepared in a reducing environment (see Experimental), thus they are expected to

• , 124.6, 122.2, 51.0, 45.7, 20.4. HRMS calcd. for C29H28N2O2: 436.2151; found 436.2147. Mechanism of Au(III)-catalyzed benzannulation between aromatic carbonyls and alkynes. X-ray analysis of the metal films used in this benzannulation study. Panels a–e are scanning-electron micrographs (SEM) of all films

• Western, University of Western Ontario, London, ON for the SEM and EDX measurements.

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• the OH group by reduction of the tosylate 207 with LiBEt3H yielded the SEM ether 208. Conversion to the vinyl iodide 209 followed by Pd0-catalyzed coupling with the (S)-alkynyl butenolide 210 gave the asiminocin precursor 211. Selective hydrogenation of the enyne moiety with diimide and cleavage of

• the SEM protecting groups completed the synthesis of triol 198, which exhibited 1H and 13C NMR spectra indentical to those of asiminocin [81]. Total synthesis of asiminecin In 1997, Marshall’s group reported the total synthesis of asiminecin (212) starting from aldehyde 204 and the OTBS allylic

• stannane 205 (Scheme 28) [82]. Addition of the latter to the former in the presence of InCl3 afforded the anti adduct 213 which was protected as the SEM ether 214. Hydrogenation followed by OTBS cleavage with TBAF and selective silylation of the primary alcohol with TBSCl and Et3N-DMAP led to the secondary