Substrate-Dependent Mechanistic Divergence in Decarboxylative Heck Reaction at Room Temperature
作者:Asik Hossian、Samir Kumar Bhunia、Ranjan Jana
DOI:10.1021/acs.joc.6b00100
日期:2016.3.18
We report herein a Pd(II)-catalyzed Heck-type coupling between arene carboxylic acids and alkenes at room temperature. Mechanistically, the reaction proceeds in two distinct pathways where electron-rich substrates undergo a palladium(II)-catalyzed decarboxylation and electron-deficient substrates proceed through silver(I)-assisted decarboxylation. Dimethylsulfoxide (DMSO) or sulfide ligands have positive
An efficient Pd-catalyzed decarboxylative cross-coupling reaction of simple enamides was achieved. Depending on the choice of the nitrogen-protecting group, a site-selective synthesis of mono- or diarylated framework(s) was performed under mild conditions. This unprecedented reactivity could be applied to the synthesis of a range of 2- or 2,4-diarylated nitrogen-containing bioactive derivatives.
Novel Chiral Dendritic Diphosphine Ligands for Rh(I)-Catalyzed Asymmetric Hydrogenation: Remarkable Structural Effects on Catalytic Properties
作者:Bing Yi、Qing-Hua Fan、Guo-Jun Deng、Yue-Ming Li、Li-Qin Qiu、Albert S. C. Chan
DOI:10.1021/ol036512a
日期:2004.4.1
series of dendritic ligands with a chiral diphosphine located at the focal point have been synthesized through coupling of pyrphos 2 with Frechet-type polyether dendron 3. The relationship between the primary structure of the dendrimer and its catalytic properties was established in the Rh-catalyzed asymmetric hydrogenation of alpha-acetamido cinnamic acid 4. A remarkable structural effect on catalytic