Synthesis of Functionalized Indoles via Palladium-Catalyzed Cyclization of N-(2-allylphenyl) Benzamide: A Method for Synthesis of Indomethacin Precursor

Abstract

We developed an efficient method for synthesis of substituted N-benzoylindole via Pd(II)-catalyzed C–H functionalization of substituted N-(2-allylphenyl)benzamide. The reaction showed a broad substrate scope (including N-acetyl and N-Ts substrates) and substituted indoles were obtained in good to excellent yields. The most distinctive feature of this method lies in the high selectivity for N-benzoylindole over benzoxazine, and this is the first example of Pd(II)-catalyzed synthesis of substituted N-benzoylindole. Notably, this new method was applied for the synthesis of key intermediate of indomethacin.

Allylation of C‐, N‐, and O‐Nucleophiles via a Mechanochemically‐Driven Tsuji–Trost Reaction Suitable for Late‐Stage Modification of Bioactive Molecules

“…Subsequently, we explored the versatility of substituted allyl ammonium salts (Scheme 2) with O-, N-, and Cnucleophiles (42)(43)(44)(45)(46)(47)(48)(49)(50)(51). These salts can be readily derived from the respective allyl chlorides by reacting with Me 3 N solution.…”

“…Alternatively, the acceleration of the reaction by addition of water might be due to the effect of liquid assisted grinding, [25] or a combination of both factors. Interestingly, when employing terminal allyl ammonium compounds, exclusively linear products were obtained with moderate to excellent yields (44)(45)(46)(49)(50)(51).…”

Allylation of C‐, N‐, and O‐Nucleophiles via a Mechanochemically‐Driven Tsuji–Trost Reaction Suitable for Late‐Stage Modification of Bioactive Molecules

“…The authors have cited additional references within the Supporting Information. [ 20 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]…”

Palladium-Catalyzed Oxidant Dependent Switchable Aza-Wacker Cyclization and Oxidative Dimerization of Benzimidates

“…aza-Wacker-type reaction of olefins is an important topic in Pd­(II)-catalysis with amines, carbazoles, carbamates, amides being commonly utilized in intermolecular palladium-catalyzed oxidative amination reaction . Recently, there has been significant progress in intramolecular aza-Wacker type reaction; , however, the same with O -homoallyl benzimidates in intramolecular fashion is seldom explored.…”