Ruthenium(II)‐Catalyzed C−H Alkenylation of 1,8‐Naphthalimide with Cyclic Imide as a Weakly Coordinating Directing Group

Abstract

Ruthenium-catalyzed direct CÀ H alkenylation of 1,8-naphthalimide has been explored using cyclic imide as a weak directing group and successfully introduce alkenyl group(s) into 1,8-naphthalimide skeleton at the inactive C2 and/or C7 position(s). The aromatic ring of 1,8-naphthalimide is substituted with electron-withdrawing and -donating groups, and N-alkyl/aryl groups on cyclic imide are compatible in these coupling reactions.

Transition-Metal-Catalyzed C–H Activation Reactions for the Creation and Modification of Organic Fluorophores

“…183,184 In the context of heteroatom-directed C−H activation/functionalization reactions, the cyclic imide group(s) of perylene imides, behave as a weak-coordinating group to weakly bind a transition metal and activate the proximal ortho-C−H bond for efficiently reacting with various coupling partners to deliver the ortho-functionalized perylene imide molecules (Scheme 70). [185][186][187][188][189][190][191][192][193][194][195][196][197][198][199][200][201][202][203][204] This C−H activation/functionalization strategy modifies the optical and physical properties of these rylene imides. Thereafter, in 2010, Marks and Wasielewski synthesized the ortho-alkylated perylene diimide, perylene monoimide, naphthalene diimide and naphthalene monoimide derivatives and investigated their photophysics and redox properties (Scheme 71).…”

“…In 2022, Paul and co-workers employed a similar approach to functionalize naphthalene monoimides (NMIs) by introducing alkene functional groups at two ortho-positions of the NMIs in the synthesis of ortho-alkenylated NMIs. 196 Scheme 74 Transition metal-catalyzed ortho-C−H tetraolefination of perylene diimides.…”

“…In 2022, Paul and co-workers employed a similar approach to functionalize naphthalene monoimides (NMIs) by introducing alkene functional groups at two ortho-positions of NMIs in the synthesis of ortho-alkenylated NMIs. 193 In 2017, the Lin and Zhang research groups introduced a novel protocol for establishing carbon-iodine bonds at the ortho-positions of PDIs. This breakthrough was achieved through a rhodium(III)-catalyzed C-H activation/iodination strategy (Scheme 75).…”

“…4,181 In the context of heteroatom-directed C-H activation/functionalization reactions, the cyclic imide group(s) of perylene imides behave as a weak-coordinating group to weakly bind a transition metal and activate the proximal ortho-C-H bond for efficient reaction with various coupling partners to deliver the ortho-functionalized perylene imide molecules (Scheme 70). [182][183][184][185][186][187][188][189][190][191][192][193][194][195][196][197][198][199][200][201] This C-H activation/functionalization strategy modifies the optical and physical properties of these rylene imides.…”

Rh(III)-Catalyzed ortho-C–H Amidation of Naphthalene and Perylene Monoimides

“…Because of this unique property, the synthesis of functionalized NMI remains a topic of current interest and has inspired synthetic chemists to find efficient routes for its synthesis. Various approaches for the functionalization of NMI are reported in literature, , such as electrophilic nitration/condensation at the bay -position. , Likewise, electrophilic nitration of 1,8-naphthalic anhydride, S N Ar azidation, and a cross-coupling reaction of 4-bromo-1,8-naphthalimide at the peri -position are also reported . A survey of the literature indicates that synthetic routes for the ortho -C–N bond formation are yet untested on NMI.…”