2756-97-0Relevant articles and documents
Pd(ii)/Lewis acid catalyzed regioselective olefination of indole with dioxygen
Tan, Chen,Jiang, Hongwu,Zeng, Miao,Li, Kaiwen,Chen, Zhuqi,Yin, Guochuan
, p. 1425 - 1435 (2022/02/25)
Transition metal ion catalyzed indole olefination through C-H activation is a convenient protocol to synthesize versatile bioactive vinylindole compounds; however, in most cases, stoichiometric amounts of oxidants were necessary to accomplish the catalytic cycle. The present study describes a Pd(ii)/LA (LA: Lewis acid) catalyzed indole olefination with dioxygen as the sole oxidant. The olefination reaction with electron-rich olefins proceeded smoothly through the pyrrolyl N-carboxamide group directed remote C-H activation at the C3 position of the indole with the Pd(ii)/LA catalyst, whereas Pd(ii) alone was a very sluggish catalyst under identical conditions. For the electron-deficient olefins, the directing N-carboxamide group was not essential for olefination with this Pd(ii)/LA catalyst, demonstrating a different olefination pathway from that of electron-rich olefins. Remarkably, 1H NMR kinetics disclosed that olefination proceeded much faster with electron-rich olefins than with electron-deficient ones.
Synthesis of 3-alkenylindoles through regioselective C-H alkenylation of indoles by a ruthenium nanocatalyst
Banerjee, Srirupa,Chatterjee, Debnath,Paul, Abhijit,Yadav, Somnath
supporting information, p. 140 - 148 (2020/03/27)
3-Alkenylindoles are biologically and medicinally very important compounds, and their syntheses have received considerable attention. Herein, we report the synthesis of 3-alkenylindoles via a regioselective alkenylation of indoles, catalysed by a ruthenium nanocatalyst (RuNC). The reaction tolerates several electron-withdrawing and electron-donating groups on the indole moiety. Additionally, a robustness screen has also been employed to demonstrate the tolerance of several functional groups relevant to medicinal chemistry. With respect to the Ru nanocatalyst, it has been demonstrated that it is recoverable and recyclable up to four cycles. Also, the catalyst acts through a heterogeneous mechanism, which has been proven by various techniques, such as ICPMS and three-phase tests. The nature of the Ru nanocatalyst surface has also been thoroughly examined by various techniques, and it has been found that the oxides on the surface are responsible for the high catalytic efficiency of the Ru nanocatalyst.
MOFs Extend the Lifetime of Pd(II) Catalyst for Room Temperature Alkenylation of Enamine-Like Arenes
Cirujano, Francisco G.,Leo, Pedro,Vercammen, Jannick,Smolders, Simon,Orcajo, Gisela,De Vos, Dirk E.
supporting information, p. 3872 - 3876 (2018/09/25)
The synthesis of pharmaceutically relevant scaffolds, such as substituted indoles or uracils, through the alkenylation of the “enamine-like” aromatic C?H bond is performed at room temperature using catalytic amounts of Pd(OAc)2 in the presence
