Study On Alkenylation Of Indoline With C - 7 Catalyzed By Pd (Ⅱ)

The indoline nucleus is a ubiquitous structural unit in bioactive natural products, Pharmaceuticals and organic materials, and most of them have been used in our lives. More recently, some C-7 alkenylation of indolines have been reported to display interesting biological activities, such as:anticancer agents、antiviral agents and antibacterial agents. Over the past decades, the development of efficient strategies for the functionalization of indoline nucleus has been received considerable attention in organic synthesis, especially the metal-catalyzed direct C-7 C-H alkenylation. In spite of some important advances in the field, some challenging issues still remain. For example, large excess of oxidant (such as:Cu(OAc)2, BQ) was used in the reaction system, which not only increased the cost of the reaction, but also led to stoichiometric amounts of the reduced external oxidant as waste that a lot trouble for work-up; and in some catalysis system, substrate scope was limited and some cases were of poor yield.In the chapter, we disclose a general, efficient and structurally versatile palladium(Ⅱ)-catalyzed intermolecular C-7 alkenylation of indolines with alkenes. Our method relies on the N-(2-pyridyl)sulfonyl directing group, which can be easily installed and removed in reaction. Most importantly, compared with Cu(OAc)2 and BQ, oxygen is an ideal oxidant and offers attractive industrial prospects in terms of green and sustainable chemistry while no reduced waste is produced. Apart from acrylonitrile, other products are E-isomers at C-7 position and no other position substituted product could be detected. Moreover, indolines derivatives could be oxidized with MnO2 and DDQ to generate some useful indole compounds. So the approach also presented an efficient route for synthesis of C-7 alkenylation of indoles.