Rhodium-Catalyzed [2 + 2 + 2] Cycloaddition of Alkenyl Isocyanates and Alkynes
作者:Robert T. Yu、Tomislav Rovis
DOI:10.1021/ja057803c
日期:2006.3.1
rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition between alkenyl isocyanates and alkynes has been developed. Heating a mixture of an alkenyl isocyanate and a symmetrical internal alkyne in the presence of [Rh(ethylene)2Cl]2/P(4-OMe-C6H4)3 in toluene delivers substituted indolizinones and quinolizinones. Depending on the substrates, a rare fragmentation of the isocyanate unit can be involved within the cycloaddition process
Ruthenium-Catalyzed <i>trans</i>-Hydroalkynylation and <i>trans</i>-Chloroalkynylation of Internal Alkynes
作者:Nagaraju Barsu、Markus Leutzsch、Alois Fürstner
DOI:10.1021/jacs.0c08582
日期:2020.11.4
[Cp*RuCl]4 catalyzes the addition of iPr3SiC≡CX (X = H, Cl) across internal alkynes with formation of 1,3-enyne or 1-chloro-1,3-enyne derivatives, respectively; the reaction follows an unorthodox trans-addition mode. The well-balanced affinities of the different reaction partners to the ruthenium catalyst ensure that crossed addition prevails over homodimerization of the individual components, as can
Water-Soluble Cationic Conjugated Polymers: Response to Electron-Rich Bioanalytes
作者:Sébastien Rochat、Timothy M. Swager
DOI:10.1021/ja4095395
日期:2013.11.27
We report the concise synthesis of a symmetrical monomer that provides a head-to-head pyridine building block for the preparation of cationic conjugated polymers. The obtained poly(pyridinium-phenylene) polymers display appealing properties such as high electron affinity, charge-transport upon n-doping, and optical response to electron-donating analytes. A simple assay for the optical detection of low micromolar amounts of a variety of analytes in aqueous solution was developed. In particular, caffeine could be measured at a 25 mu M detection limit. The reported polymers are also suitable for layer-by-layer film formation.