Rhodium-catalyzed oxidative coupling of N-acyl anilines with alkynes using an acylamino moiety as the traceless directing group

Abstract

A rhodium-catalyzed oxidative annulation of N-acyl anilines with alkynes was developed by using the acylamino group as a traceless directing group for the first time.

Amides as Weak Coordinating Groups in Proximal C–H Bond Activation

“…Zhang and coworkers reported a unique approach to rhodium‐catalyzed oxidative annulation of N ‐acyl anilines with alkynes by utilizing the acylamino group as a traceless directing group (Scheme ) . The notable feature of this protocol was that it readily offers 1,2,3,4‐tetrasubstituted naphthalenes as sole products, which is opposite to the previous reports in which nitrogen heterocycles were obtained , …”

Regioselective Transition-Metal-Catalyzed C–H Functionalization of Anilines

“…This chemistry was expanded upon by Zhang and co-workers who displayed, under complementary rhodium catalysis, that the anilide directing group could undergo in situ removal resulting in a traceless directing group strategy. 28 In 2011, Kwong and co-workers reported the orthoacylation of acetanilide derivatives utilizing Pd(TFA) 2 as the catalyst and TBHP as the oxidant (Scheme 10). This transformation was shown to offer wide scope with a variety of arenes and aryl and alkyl aldehyde coupling partners undergoing this chemistry.…”

[2+2+2] Annulation of N-(1-Naphthyl)acetamide with Two Alkynoates via Cleavage of Adjacent C–H and C–N Bonds Catalyzed by an Electron-Deficient Rhodium(III) Complex

“…In this paper, we have established that the electron-deficient cationic Cp E -rhodium(III) complex is able to catalyze the non-oxidative [2+2+2] annulation of N -(1-naphthyl)acetamide ( 2c ) with two alkynoates 3 via cleavage of the adjacent C–H and C–N bonds, leading to densely substituted phenanthrenes 5 , under mild conditions (at 40 °C under air) (Scheme 1, middle). Although several examples of the transition-metal-catalyzed decarboxylative and oxidative [2+2+2] annulation of benzoic acids with two alkynoates via cleavage of the adjacent C–H and C–C bonds, leading to densely substituted naphthalenes, have been reported [24,25,26,27], only a single example of the non-oxidative [2+2+2] annulation via cleavage of the adjacent C–H and C–N bonds, in which the acylamino moiety is employed as a traceless directing group, has been reported in the neutral Cp*-rhodium(III) complex-catalyzed synthesis of tetraarylnaphthalenes from N -acylanilines and two diarylacetylenes at elevated temperature (110 °C) (Scheme 1, bottom) [28].…”