30405-78-8Relevant articles and documents
Sonogashira cross-couplings of dehydroamino acid derivatives and phenylacetylenes
Abreu, Ana S.,Ferreira, Paula M. T.,Queiroz, Maria-Joao R. P.,Gatto, Emanuela,Venanzi, Mariano
, p. 3985 - 3991 (2004)
Several phenylacetylenes were coupled under Sonogashira cross-coupling conditions with the methyl esters of N-(tert-butoxycarbonyl)-(E)-β-bromo- or -β,β-dibromodehydroalanine, to give β-substituted or β,β-disubstituted dehydroalanines, respectively. The β-substituted dehydroalanines were obtained in good to high yields (60-90%) under the usual Sonogashira conditions (1 equiv. of the phenylacetylene, 1 mol % of [Pd(PPh3)4], 2 mol % of CuI, 18 equiv. of NEt 3 in acetonitrile, 24 h at room temp.), with retention of stereochemistry. The β,β-disubstituted dehydroalanines were, in turn, obtained in moderate to good yields (44-63%) under modified Sonogashira conditions (4 equiv. of the phenylacetylene, 10 mol % of [PdCl 2(PPh3)2], 20 mol % of CuI, 1.4 equiv. of Cs2CO3 in acetonitrile, 2 h at reflux). In the latter reactions, some phenylacetylene dimer and the (E) isomer of the monosubstituted coupled products were also isolated to some extent. The Sonogashira products obtained from the 4-bromophenylacetylene were allowed to react with functionalized benzo[b]thiophenes under C-C or C-N palladium-catalyzed cross-coupling conditions. Preliminary fluorescence studies were performed for mono- and disubstituted (4-aminophenyl)acetylenic dehydroamino acids and for the benzo[b]-thiophene derivatives. The results showed that some of the dehydroalanines prepared can be used as fluorescent probes. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Integrative self-sorting synthesis of a Fe8Pt6L 24 cubic cage
Smulders, Maarten M. J.,Jiménez, Azucena,Nitschke, Jonathan R.
, p. 6681 - 6685 (2012)
96 bonds were formed when 62 building blocks (heterotopic ligands with FeII and PtII ions) self-assembled in a one-pot reaction into a heterometallic Fe8Pt6L24 cubic cage (see model, Fe purple, Pt orange, N blue). The dynamic nature of this method also allowed an efficient cage-to-cage conversion: a tetrahedral Fe4L 6 cage was converted into the Fe8Pt6L 24 cube, which was subsequently converted into a second tetrahedral Fe4L'6 cage. Copyright
Diacetylene Functionalized Covalent Organic Framework (COF) for Photocatalytic Hydrogen Generation
Pachfule, Pradip,Acharjya, Amitava,Roeser, Jér?me,Langenhahn, Thomas,Schwarze, Michael,Schom?cker, Reinhard,Thomas, Arne,Schmidt, Johannes
supporting information, p. 1423 - 1427 (2018/02/09)
Covalent organic frameworks (COFs) are crystalline, highly porous, two- or three-dimensional polymers with tunable topology and functionalities. Because of their higher chemical stabilities in comparison to their boron-linked counterparts, imine or β-ketoenamine linked COFs have been utilized for a broad range of applications, including gas storage, heterogeneous catalysis, energy storage devices, or proton-conductive membranes. Herein, we report the synthesis of highly porous and chemically stable acetylene (-C≡C-) and diacetylene (-C≡C-C≡C-) functionalized β-ketoenamine COFs, which have been applied as photocatalyst for hydrogen generation from water. It is shown that the diacetylene moieties have a profound effect as the diacetylene-based COF largely outperforms the acetylene-based COF in terms of photocatalytic activity. As a combined effect of high porosity, easily accessible diacetylene (-C≡C-C≡C-) functionalities and considerable chemical stability, an efficient and recyclable heterogeneous photocatalytic hydrogen generation is achieved.
Electronic properties of hyperbranched compounds derived by pyrrole
Fomina, Lioudmila,Sánchez, Jorge Godínez,Olivares,Cuppo,Sansores, L. Enrique,Salcedo, Roberto
, p. 534 - 541 (2014/07/22)
The electronic structure of hyperbranched polymers obtained from para-diaminodiphenyldiacetylenes as AB2 type monomers by one-step polymerization is studied using DFT calculations. Five generations are modelled with optimization at each step. As the molecule grows it shows a helical shape conserving the C2 symmetry with wing like fragments covering the backbone. There is accidental degeneracy of the HOMO with the HOMO-1 and of the HOMO-2 with the HOMO-3. The LUMO is always located at the backbone and the HOMO set at the dianyline-pyrrole fragment. The HOMO-LUMO gap decreases as the molecule grows. Conductivity measurements as well as microscopy studies of para-hyperbranched polymer were carried out. Conductivity measurements as a function of temperature show semiconductor behavior. Optical microscopy reveals a macroscopic crystalline structure of this hyperbranched polymer.
