l-(−)-Quebrachitol as a Ligand for Selective Copper(0)-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles

Abstract

L-(−)-Quebrachitol (QCT) has been found as a ligand of copper powder for selective N-arylation of nitrogencontaining heterocycles with aryl halides. Furthermore, another potential catalytic system (copper powder/QCT/t-BuOK) was successfully adapted to unactivated aryl chlorides.

Recent Progress Concerning the N-Arylation of Indoles

“…In the case of the glucosamine ligand L2 , the formation of a radical intermediate T4-1 was proposed, although the formation of this intermediate has not been experimentally verified. The use of other natural substances in this regard includes the use of N -alkyl-glucosamine as a sugar-based surfactant [ 118 ], alpha- d -galacturonic acid L3 [ 119 ], and l -(-)-quebrachitol L4 [ 120 ] as ligands for the copper-catalyzed N -arylation of indoles and nitrogen-containing substances.…”

Functionalization of superparamagnetic Fe3O4@SiO2nanoparticles with a Cu(II) binuclear Schiff base complex as an efficient and reusable nanomagnetic catalyst forN‐arylation of α‐amino acids and nitrogen‐containing heterocycles with aryl halides

“…In the last decades, copper complexes (Cu(0), (I), or (II)) along with various ligands have been used for the C-N cross-coupling reactions (known as amination or N-arylation) of aryl halides with different type of amines, [1][2][3][4][5][6] because of the lower cost of copper salts and its application in the cross-coupling reactions as similar as Pd. [7,8] The first copper catalyzed C-N bond formation was developed by Ullman and Goldberg. [9,10] Various types of N-arylation have been reported in the literature that some examples come as follows: N-arylation of imidazoles, [11][12][13][14][15][16] Cu(I)-catalyzed N-arylation of indoles, [17] C-N coupling of aniline with terminal alkynes (synthesis of α-ketoamides), [18] copper-mediated C-N coupling reaction of azido compounds and aryl halides, [19] N-arylation of aryl halides with alkyl amine using CuBr catalyst which benefits from phosphoramidite as a ligand, [20] Cu(I)-catalyzed N-arylation of pyrazoles, [21] N-arylation of aryl iodide with hypervalent aryl siloxanes by Cu (OAc) 2 along with a ligand, [22] N-arylation of α-amino acids catalyzed by Cu(I), [23][24][25] cross-coupling reaction of aryl halides to aryl amines catalyzed by Cu 2 O in solution of ammonia, [26] N-alkynylation of amides catalyzed by Cu(I), [27] Cu(I)-amidation catalyzed of aryl halides, [28][29][30] Ullmann-type N-arylation of anilines, [31] Cu-catalyzed intramolecular adjacent C-N coupling (asymmetric synthesis of atropisomeric compounds), [32] Cu/N,N 0dibenzyloxalamide-catalyzed N-arylation of heteroanilines, [33] Cu-catalyzed N-arylation of sulfoximines, [34] Cu-catalyzed decarboxylative N-arylation...…”

Copper Mediated Direct Amination: Synthesis of 1,2,3,15 a‐tetrahydro‐14H‐pyrrolo[1,2‐a]quinazolino[3,2‐c]quinazolin‐14‐onederivatives via 2‐(2‐bromophenyl)quinazolin‐4(3H)‐ones

“…The following reaction mechanism is proposed based on experimental observations and previous literature reports (Scheme 3). [17–22] The reaction profile clearly indicates that the imine intermediate ( I ) is generated from the initial dehydrative coupling of anthranilamide and 2‐bromobenzaldehyde substrates. Here, the copper‐catalyst facilitates the imine isomerization to form the active species ( II ).…”