10336-16-0Relevant articles and documents
Electrochemical Synthesis of Carbazoles by Dehydrogenative Coupling Reaction
Kehl, Anton,Schupp, Niclas,Breising, Valentina M.,Schollmeyer, Dieter,Waldvogel, Siegfried R.
, p. 15847 - 15851 (2020)
A constant current protocol, employing undivided cells, a remarkably low supporting electrolyte concentration, inexpensive electrode materials, and a straightforward precursor synthesis enabling a novel access to N-protected carbazoles by anodic N,C bond formation using directly generated amidyl radicals is reported. Scalability of the reaction is demonstrated and an easy deblocking of the benzoyl protecting group is presented.
Electrochemical Dehydrogenative C(sp2)?H Amination
Puthanveedu, Mahesh,Khamraev, Vladislav,Brieger, Lukas,Strohmann, Carsten,Antonchick, Andrey P.
supporting information, p. 8008 - 8012 (2021/05/07)
A transition-metal-free direct electrolytic C?H amination involving an electrochemically generated nitrenium ion intermediate has been developed. The electrosynthesis takes place in the absence of any organoiodine catalysts and is enabled by an in situ ge
Transition-metal-free and organic solvent-free conversion of N-substituted 2-aminobiaryls into corresponding carbazoles via intramolecular oxidative radical cyclization induced by peroxodisulfate
Natarajan, Palani,Priya,Chuskit, Deachen
supporting information, p. 5854 - 5861 (2017/12/26)
An atom-economical and environmentally benign approach for the synthesis of N-substituted carbazoles from analogous 2-aminobiaryls using peroxodisulfate in water is reported. The reactions proceeded through an intramolecular oxidative radical cyclization
Pd(II) pincer type complex catalyzed tandem C-H and N-H activation of acetanilide in aqueous media: A concise access to functionalized carbazoles in a single step
Arumugam, Vignesh,Kaminsky, Werner,Nallasamy, Dharmaraj
supporting information, p. 3295 - 3301 (2016/06/13)
One-pot, tandem C-H and N-H activation of acetanilides with aryl boronic acids to realize functionalized carbazoles was conveniently performed under aerobic conditions using a novel NNO pincer type Pd(ii) complex [Pd(L)Cl] (where L = nicotinic acid (phenyl-pyridin-2-yl-methylene)-hydrazide or furan-2-carboxylic acid (phenyl-pyridin-2-yl-methylene)-hydrazide) as a catalyst in neat water and a very low (0.01 mol%) amount of catalyst. It is worth noting that recyclability up to six consecutive runs and column chromatography free isolation of the title heterocycles in an excellent yield are achieved.
Synthesis of Carbazoles by a Merged Visible Light Photoredox and Palladium-Catalyzed Process
Choi, Sungkyu,Chatterjee, Tanmay,Choi, Won Joon,You, Youngmin,Cho, Eun Jin
, p. 4796 - 4802 (2015/08/18)
Carbazoles have attracted great interest in recent years for a variety of applications in organic and medicinal chemistry as well as in materials science. In this work, an efficient method for the synthesis of carbazoles through the intramolecular C-H bon
Pd(II)-catalyzed intramolecular C-H activation/C-C cross coupling for the synthesis of carbazoles from diaryl acetamides
Wang, Sichang,Mao, Hui,Ni, Zhangqin,Pan, Yuanjiang
supporting information; scheme or table, p. 505 - 508 (2012/02/01)
Pd(II)-catalyzed intramolecular C-H activation/C-C cross coupling within N,N-diphenyl-acetamides allows the efficient formation of differently substituted carbazoles. In this cross-dehydrogenative coupling, many different functional groups are tolerated and the starting material N,N-diphenyl- acetamides can be easily prepared in one step from commercially available acetanilides and iodobenzenes.
Organocatalytic, oxidative, intramolecular C-H bond amination and metal-free cross-amination of unactivated arenes at ambient temperature
Antonchick, Andrey P.,Samanta, Rajarshi,Kulikov, Katharina,Lategahn, Jonas
supporting information; experimental part, p. 8605 - 8608 (2011/11/05)
The twinkling of an I: In a new atom-economical and environmentally friendly organocatalytic method for intramolecular C-H amination, the C-N bond forms at ambient temperature by abstraction of two atoms of hydrogen; only acetic acid and water are formed
Intramolecular oxidative C-N bond formation for the synthesis of carbazoles: Comparison of reactivity between the copper-catalyzed and metal-free conditions
Cho, Seung Hwan,Yoon, Jungho,Chang, Sukbok
supporting information; experimental part, p. 5996 - 6005 (2011/06/11)
New synthetic procedures for intramolecular oxidative C-N bond formation have been developed for the preparation of carbazoles starting from N-substituted amidobiphenyls under either Cu-catalyzed or metal-free conditions using hypervalent iodine(III) as an oxidant. Whereas iodobenzene diacetate or bis(trifluoroacetoxy)iodobenzene alone undergoes the reaction to provide carbazole products in moderate to low yields, combined use of copper(II) triflate and the iodine(III) species significantly improves the reaction efficiency, giving a more diverse range of products in good to excellent yields. On the basis of mechanistic studies including kinetic profile, isotope effects, and radical inhibition experiments, the copper species is proposed to catalytically activate the hypervalent iodine(III) oxidants. The synthetic utility of the present approach was nicely demonstrated in a direct synthesis of indolo[3,2-b]carbazole utilizing a double C-N bond formation.
Outer-sphere electron transfer from carbazoles to halomethanes. Reduction potentials of halomethanes measured by fluorescence quenching experiments.
Bonesi, Sergio M.,Erra-Balsells, Rosa
, p. 1583 - 1595 (2007/10/03)
Kinetic studies on the photoinduced electron transfer reduction of a variety of halomethanes in acetonitrile and ethanol at 298 K are reported in terms of the quenching rate constants (kq) with a series of reductants (carbazoles and anthracenes) whose one-electron oxidation potentials (Eox) have been measured again in the present work vs. SCE and independently vs. ferrocene. The Rehm-Weller Gibbs energy relationship is applied to determine the fundamental parameters for the one-electron reduction, i.e., the one-electron reduction potentials (ERX/RX) of the halomethanes and the intrinsic barrier for the electron transfer reduction (ΔG?o). The ERX/RX- values obtained were related to the concerted electron transfer-bond breaking reduction potentials (ERX/R·+x-) and the standard free enthalpies of dissociation of RX- (ΔGo,dissRX-) were estimated in each solvent. Additionally, the one-electron reduction potential (ERX/RX-) values estimated in acetonitrile were also related to different thermodynamic parameters such as electron affinity (EA), LUMO-HOMO energy differences (ΔE) and the bond dissociation energy (DRX). Optimized geometry, EA and ΔE for halomethanes were calculated by an ab initio method at the B3LYP level using 3-21G, 6-31 + G(d,p) and G-311 + G(3df,2pd) basis sets. In all these cases good linear correlations were obtained. The ΔG?o values obtained are compared with those calculated using the equation ΔG?o = λ/4 with λ = λi + λo where the solvent reorganization energy (λo) and the inner-sphere reorganization energies (λi) associated with the structural change upon the electron-transfer process were calculated, the former by using the Marcus-Hush model and the latter by using semiempirical and ab initio molecular modeling and QSAR properties. Results obtained from the preparative irradiation of carbazoles in the presence of halomethanes, which are consistent with a photoinduced electron transfer mechanism are also discussed.
On the Synthesis and Isolation of Chlorocarbazoles Obtained by Chlorination of N-Substituted Carbazoles
Bonesi, Sergio M.,Erra-Balsells, Rosa
, p. 891 - 900 (2007/10/03)
Chloro derivatives of N-methylcarbazole (1), N-phenylcarbazole (2), N-acetylcarbazole (3), N-benzoylcarbazole (4) and 2-methoxy-N-methylcarbazole are synthesized. They are compounds 1a, 1b, 1e, 1d, 1e, 2a, 2b, 3a, 3b, 3c, 3d, 4a, 4b, 5a, 5b, 5c, 5d and 5e
