Rhodium-catalyzed synthesis of substituted isoquinolones via a selective decarbonylation/alkyne insertion cascade of phthalimides

Abstract

A rhodium-catalyzed decarbonylation/alkyne insertion cascade of phthalimides with alkynes has been established.

Isoquinolone Syntheses by Annulation Protocols

“…In addition, the similar catalyst system can also catalyze a decarbonylative addition of phthalimides to internal alkynes to afford highly substituted isoquinolones (Scheme 25) [103]. The similar transformation can take place using CoI 2 /phosphine/Ag 2 CO 3 [104], and Rh(PPh 3 ) 2 (CO)Cl as the catalyst systems [105]. The annulation reaction between benzocyclobutenols and isocyanates catalyzed by [RhOH(cod)] 2 can also produce isoquinolone derivatives with excellent regioselectivity and functional-group tolerance (Scheme 27) [107].…”

LiN(SiMe3)2/KOtBu-Promoted Synthesis of Isoquinolone Derivatives from 2-Methylaryl Aldehydes and Nitriles

“…Isoquinolones, as a type of the most common fused six-membered heterocycles, exhibit broad medicinal properties, including antitumor, antiobesity, antiviral, and other effects . In the past years, various synthetic methods for isoquinolones have been reported, including denitrogenative/decarbonylative alkyne insertion, carbonylation/decarboxylation, C–C bond activation of benzocyclobutenols, cyclocondensation of 2-alkylnyl benzaldehydes with primary amines, intramolecular annulation, isomerization of (diarylmethylidene)-3,4-dihydroisoquinolin-1­(2 H )-ones, Sonogashira coupling/Schmidt reaction, and Diels–Alder reaction of arynes with 4,5-disubstituted oxazoles followed by dehydrogenation–aromatization/tautomerization . However, most of the starting materials in these methods are not commercially available, and thus, the substrate scope is generally limited.…”

Rh-Catalyzed Cascade C-H Activation/Annulation of N-Hydroxybenzamides and Propargylic Acetates for Modular Access to Isoquinolones

“…Recently, the transition-metal-catalyzed oxidative cyclization of N -substituted benzamides with symmetrical alkynes or diazos via C-H bond activation has been an efficient method for constructing N -protected isoquinolone derivatives [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Meanwhile, many other substrates bearing the N -directing group have also been used to construct an isoquinolone scaffold through the C-H activation/annulation strategy [ 29 , 30 , 31 ]. Despite these achievements, directing access to NH-free isoquinolone scaffolds via cascade C-H activation/annulation has attracted our great interest [ 32 ].…”