1,3-Diynes synthesis by homo-coupling of terminal alkynes using a Pd(PPh3)4/Ag2O simple catalyst system
作者:Xiujuan Feng、Ziran Zhao、Fan Yang、Tienan Jin、Yongjie Ma、Ming Bao
DOI:10.1016/j.jorganchem.2011.01.022
日期:2011.4
copper salt-free palladium-catalyzed homo-coupling reaction of terminalalkynes proceeded efficiently in the presence of silver(I) oxide, which served as both activator and oxidant, in tetrahydrofuran at 60 °C to achieve satisfactory yields of 1,3-diyne compounds. It was demonstrated for the first time by means of XPS analysis that Pd(0) species can be oxidated to Pd(II) by silver(I) oxide.
Synthesis and Characterization of Polyyne Porphyrins
作者:Kazuhiro Maruyama、Shigeki Kawabata
DOI:10.1246/bcsj.63.170
日期:1990.1
A series of conjugated polyyne porphyrins, in which two porphyrin macrocycles are connected with both ends of diarylpolyyne through aromatic ring, has been prepared and their spectroscopic behaviors were investigated. Diarylpolyyne consisting of aryl group and conjugated triple bond system have rigid and linear structure, and the two porphyrins are held at a fixed geometry and a determined distance. In their absorption spectra, porphyrin Soret bands were red- or blue-shifted depending on their edge-to-edge or face-to-face orientation.
Direct catalytic asymmetric synthesis of highly functionalized (2-ethynylphenyl)alcohols via Barbas–List aldol reaction: scope and synthetic applications
作者:Dhevalapally B. Ramachary、Rumpa Mondal、R. Madhavachary
DOI:10.1039/c2ob25563d
日期:——
diastereo- and enantioselectivities was achieved by Barbas–List aldol (BLA) reaction of 2-alkynylbenzaldehydes 1 with various ketones 2 in the presence of trans-4-OH-L-proline or L-prolinamide derivative 3/4 as catalyst at the ambient temperature or −35 °C. This method also gives first time access to the novel double aldoladdition compounds 6, which are of medicinal importance. Chiral functionalized (
Synthesis and Spectroscopic Investigation of Directly Conjugated Polyyne Porphyrins
作者:Kazuhiro Maruyama、Shigeki Kawabata
DOI:10.1246/bcsj.62.3498
日期:1989.11
A series of conjugated polyyne porphyrin, in which porphyrin macrocycle is directly connected with one end of diarylpolyyne through aromatic ring, has been prepared and their spectroscopic behaviors were investigated. Diarylpolyynes consisting of aryl group and conjugated triple bond system have rigid and linear structure, and the two chromophores are held at a fixed geometry and a determined distance. The UV-vis absorption spectra of these compounds showed strong conjugative interaction, showing broadening of their spectra and slightly red shifted porphyrin Soret bands with increasing the number of acetylenic bond. From their fluorescence excitation spectra energy transfer efficiencies from polyyne moiety to porphyrin moiety were estimated. The energy transfer efficiencies were almost unity regardless of their substituted position, geometry, and orientation.