Reaction of Isoquinolin‐1(2H)‐Ones with Methylenecyclopropanes via Rhodium(III)‐Catalyzed C−H Activation

Abstract

Herein, we report a Rh(III)‐catalyzed 1,3‐dienylation of isoquinolin‐1(2H)‐ones through C−H activation. The present reaction enables the preparation of 3‐(buta‐1,3‐dien‐2‐yl)isoquinolin‐1(2H)‐ones through the direct cross‐coupling reaction of readily available isoquinolin‐1(2H)‐ones with methylenecyclopropanes, while tolerating many sensitive functional groups. Therefore, this method provides an efficient and convenient approach for modification of interesting molecules.magnified image

Exploiting Strained Rings in Chelation Guided C−H Functionalization: Integration of C−H Activation with Ring Cleavage

“…This Rh III ‐catalyzed C−H activation/ annulation offers bridged systems containing isoxazolidine and pyrazolone skeletons as a single diastereomer . Recently, Zhu and co‐workers employed MCPs in Rh III ‐catalyzed C−H activation of isoquinolin‐1(2 H )‐ones (Scheme ) . This method serves as an efficient and convenient approach for the modification of biologically active molecules.…”

A Palladium(0)‐Catalyzed C4 Site‐Selective C−H Difluoroalkylation of Isoquinolin‐1(2H)‐Ones

“…These reactions mainly occurred on benzene ring, [5] quinoline ring, [7] pyrone ring, [10] olefine [15] and others [6,8–9,11−14] . Isoquinolin‐1( 2H )‐ones are an important class of heterocycles that have been used as antipsoriasis, antidiabetes, antiviral, hypotension, and anticancer drugs [16–17] . With the development of C−H activation chemistry, various directing groups have provided straightforward ways to access C3‐ and C8‐position C−H‐functionalized products [17–18] .…”

“…Isoquinolin‐1( 2H )‐ones are an important class of heterocycles that have been used as antipsoriasis, antidiabetes, antiviral, hypotension, and anticancer drugs [16–17] . With the development of C−H activation chemistry, various directing groups have provided straightforward ways to access C3‐ and C8‐position C−H‐functionalized products [17–18] . However, as a result of remote position, only a few reactions at C4 were reported [19] .…”

Three-Component Couplings among Heteroarenes, Difluorocyclopropenes, and Water via C–H Activation

“…Transition-metal-catalyzed direct functionalization of inert C–H bonds has attracted considerable attention as it provided practitioners in the synthetic community with a powerful and convenient protocol for rapidly constructing numerous valuable molecules in an atom- and step-economic manner. − Over the past few decades, organic chemists have spent a great deal of effort in pursuing directing group (DG)-assisted C–H bond functionalization, through which a large array of desired molecules with structural diversity and complexity could be obtained by using efficient coupling partners. − Among them, strained rings such as aziridines, − cyclopropanols, − and alkylidenecyclopropanes − have stood out as charming coupling partners because they enabled rapid reconstruction of the skeleton of the product and then achieved structural complexity with the inherent ring strain being the driving force. Being one of the most appealing strained molecules, cyclopropenone has been widely applied as a building block for quick access to various heterocyclic compounds under Rh or Ru catalysis via the C–H activation strategy. − Despite the great progress that has been made, some drawbacks in the preparation of cyclopropenone such as the tedious procedure and high cost limited its further application (Scheme a).…”