- First total synthesis of the 7-oxygenated carbazole alkaloids clauszoline-K, 3-formyl-7-hydroxycarbazole, clausine M, clausine N and the anti-HIV active siamenol using a highly efficient palladium-catalyzed approach
-
A short synthesis of the 7-oxygenated carbazole alkaloids clauszoline-K, 3-formyl-7-hydrocarbazole, clausine C, clausine M, clausine N and the anti-HIV active siamenol was investigated. The synthesis was performed using a convergent palladium-catalyzed co
- Krahl, Micha P.,Jaeger, Anne,Krause, Tilo,Knoelker, Hans-Joachim
-
-
Read Online
- Copper immobilized at a covalent organic framework: An efficient and recyclable heterogeneous catalyst for the Chan-Lam coupling reaction of aryl boronic acids and amines
-
A polyimide covalent organic framework (PI-COF) with high thermal and chemical stabilities has been readily prepared from commercially available and inexpensive reagents and was employed as an effective support for heterogeneous copper. It was demonstrated that the obtained Cu@PI-COF is a highly active heterogeneous catalyst which can effectively promote the Chan-Lam coupling reaction of aryl boronic acids and amines in an open flask without the aid of any base or additive. In addition, the catalyst could be readily recovered from the reaction mixture by simple filtration and reused for at least eight cycles without any observable change in structure and catalytic activity.
- Han, Yi,Zhang, Mo,Zhang, Ya-Qing,Zhang, Zhan-Hui
-
p. 4891 - 4900
(2018/11/21)
-
- Tetradentate cyclometalated platinum complex containing 6-substituted carbazole and preparation method and application thereof
-
The invention relates to the field of blue phosphorescent tetradentate cyclometalated platinum complexes and discloses a blue phosphorescent tetradentate cyclometalated platinum complex with 6-substituted carbazole and a preparation method and application thereof. The complex herein may be a delayed fluorescent and/or phosphorescent emitter, having the advantages of high thermo-decomposition temperature, great quantum effect, blue emission, narrow emission spectrum and the like; therefore, the complex has a great application prospect in the field of blue light material, particularly the fieldof deep blue phosphorescent materials.
- -
-
Paragraph 0171; 0176; 0177
(2018/11/03)
-
- A tuned bicyclic proazaphosphatrane for catalytically enhanced n-arylation reactions with aryl chlorides
-
The N-arylation of various amines with aryl chlorides proceeded in good-to-excellent yields in the presence of P[N{(p-NMe2)C6H4CH2}CH2CH2]3N (1e, a new electron-rich proazaphosphatrane ligand) and small amounts of Pd2(dba)3 (dba = dibenzylideneacetone). This catalytic system was also very effective for the synthesis of carbazoles. An efficient palladium-catalyzed N-arylation reaction of amines under mild conditions with a tuned bicyclic proazaphosphatrane has been developed.
- Kim, So Han,Kim, Min,Verkade, John G.,Kim, Youngjo
-
p. 1954 - 1960
(2015/03/18)
-
- Stable nickel(0) phosphites as catalysts for C-N cross-coupling reactions
-
Herein we describe the design and preparation of inexpensive, air-stable nickel phosphite-based catalysts for use in the C-N cross-coupling reaction. The combination of nickel tetrakis(triphenyl phosphite) {Ni[P(OPh) 3]4} and 1,1'-bis(diphenylphosphino)ferrocene (dppf), and in particular a newly developed catalyst (dppf)Ni[P(OPh)3] 2, were found to be extremely effective in catalyzing a range of amination reactions of anilines and amines with aryl chlorides. This new catalyst system offers an alternative to the bis(cyclooctadienyl)nickel [Ni(COD)2] and palladium(0) catalysts commonly used for C-N bond formation.
- Kampmann, Sven S.,Sobolev, Alexandre N.,Koutsantonis, George A.,Stewart, Scott G.
-
supporting information
p. 1967 - 1973
(2014/07/07)
-
- Total synthesis of the cyclic monoterpenoid pyrano[3,2-a]carbazole alkaloids derived from 2-hydroxy-6-methylcarbazole
-
The synthesis of seven pyrano[3,2-a]carbazole alkaloids has been achieved using their putative biogenetic precursor 2-hydroxy-6-methylcarbazole as key intermediate. the Partner Organisations 2014.
- Gassner, Cemena,Hesse, Ronny,Schmidt, Arndt W.,Knoelker, Hans-Joachim
-
p. 6490 - 6499
(2014/08/18)
-
- Arylation with unsymmetrical diaryliodonium salts: A chemoselectivity study
-
Phenols, anilines, and malonates have been arylated under metal-free conditions with twelve aryl(phenyl)iodonium salts in a systematic chemoselectivity study. A new "anti-ortho effect" has been identified in the arylation of malonates. Several "dummy groups" have been found that give complete chemoselectivity in the transfer of the phenyl moiety, irrespective of the nucleophile. An aryl exchange in the diaryliodonium salts has been observed under certain arylation conditions. DFT calculations have been performed to investigate the reaction mechanism and to elucidate the origins of the observed selectivities. These results are expected to facilitate the design of chiral diaryliodonium salts and the development of catalytic arylation reactions that are based on these sustainable and metal-free reagents. Copyright
- Malmgren, Joel,Santoro, Stefano,Jalalian, Nazli,Himo, Fahmi,Olofsson, Berit
-
supporting information
p. 10334 - 10342
(2013/09/02)
-
- Palladium-catalyzed synthesis of natural and unnatural 2-, 5-, and 7-oxygenated carbazole alkaloids from N-arylcyclohexane enaminones
-
A palladium-catalyzed synthesis of the carbazole framework is described, including the preparation of 2-, 5-, and 7-oxygenated natural and unnatural carbazole alkaloids. A series of N-arylcyclohexane enaminones, generated by condensation of cyclohexane-1,3-dione with diverse anilines, were aromatized by a Pd(0)-catalyzed thermal treatment to afford the corresponding diarylamines. The latter were submitted to a Pd(II)-catalyzed cyclization and methylation processes to provide the desired carbazoles, including clausine V. Following an inverse strategy, a new and short total synthesis of glycoborine is also reported.
- Bautista, Rafael,Montoya, Pablo A.,Rebollar, Araceli,Burgueno, Eleuterio,Tamariz, Joaquin
-
p. 10334 - 10351
(2013/10/22)
-
- Palladium-catalyzed aerobic dehydrogenative aromatization of cyclohexanone imines to arylamines
-
Dehydrogenative aromatization of cyclohexanone imines to arylamines has been achieved using a palladium catalyst under aerobic conditions. The reaction is applicable to a variety of imines that are either preformed or generated in situ from cyclohexanone derivatives and aryl or alkylamines.
- Hajra, Alakananda,Wei, Ye,Yoshikai, Naohiko
-
supporting information
p. 5488 - 5491,4
(2012/12/12)
-
- Triaminophosphine ligands for carbon-nitrogen and carbon-carbon bond formation
-
Methods and compounds are provided for the formation of carbon-nitrogen or carbon-carbon bonds comprising reacting an amine or an aryl boronic acid with an aryl halide in the presence of a palladium catalyst, a base, and a compound of formula II:
- -
-
Page/Page column 29-30; 35
(2008/12/05)
-
- Transition metals in organic synthesis - Part 83#: Synthesis and pharmacological potential of carbazoles
-
A series of carbazole derivatives with promising pharmacological properties has been prepared using either an iron-mediated or a palladium-catalyzed synthetic approach. The carbazole alkaloids carbazoquinocin C, carbazomadurin A and B, epocarbazolin A and
- Choi, Taylor A.,Czerwonka, Regina,Forke, Ronny,Jaeger, Anne,Knoell, Jan,Krahl, Micha P.,Krause, Tilo,Reddy, Kethiri R.,Franzblau, Scott G.,Knoelker, Hans-Joachim
-
p. 374 - 385
(2008/12/23)
-
- Synthesis of oxygenated carbazoles by palladium-mediated oxidative double C-H activation of diarylamines assisted by microwave irradiation
-
Microwave irradiation in the presence of palladium acetate and traces of dimethylformamide allows the fast and efficient cyclodehydrogenation of diphenylamines into carbazoles. The scope of the microwave-assisted reaction is broader than that of the one using conventional conditions in that it allows the preparation of oxygenated carbazoles without apparent loss in yield. The applicability of the method to the preparation of carbazole alkaloids has been demonstrated by the development of a total synthesis of murrayafoline A, which proceeds in 50% overall yield from commercially available materials and is the shortest and most efficient route for the preparation of this alkaloid to date. Georg Thieme Verlag Stuttgart.
- Sridharan, Vellaisamy,Martín, Ma. Antonia,Menéndez, J. Carlos
-
p. 2375 - 2378
(2008/02/09)
-
- Scope and limitations of Pd2(dba)3/P(i-BuNCH 2CH2)3N-catalyzed Buchwald-Hartwig amination reactions of aryl chlorides
-
Proazaphosphatrane ligands in combination with Pd2(dba) 3 generate highly active catalysts for Buchwald-Hartwig amination of aryl chlorides. In particular, commercially available P(i-BuNCH 2-CH2)3N is a highly general and efficient ligand, allowing the coupling of an electronically diverse set of aryl chlorides, including chloropyridines, with a wide variety of amines using 1 mol % of Pd at 100 °C. Either a 1:1 or 2:1 ratio of ligand to Pd was found to be effective. This catalyst system performs exceptionally well for sterically hindered substrates, even with only 0.25 mol % of Pd. It is shown that NaOH can also be used as the base (instead of NaO-t-Bu) allowing functionalized substrates to participate in these reactions.
- Urgaonkar, Sameer,Verkade, John G.
-
p. 9135 - 9142
(2007/10/03)
-
- Application of a New Bicyclic Triaminophosphine Ligand in Pd-Catalyzed Buchwald-Hartwig Amination Reactions of Aryl Chlorides, Bromides, and Iodides
-
The new bicyclic triaminophosphine ligand P(i-BuNCH2) 3CMe (3) has been synthesized in three steps from commercially available materials and its efficacy in palladium-catalyzed reactions of aryl halides with an array of amines has been demonstrated. Electron-poor, electron-neutral, and electron-rich aryl bromides, chlorides, and iodides participated in the process. The reactions encompassed aromatic amines (primary or secondary) and secondary amines (cyclic or acyclic). It has also been shown that the weak base Cs2CO3 can be employed with ligand 3, allowing a variety of functionalized substrates (e.g., those containing esters and nitro groups) to be utilized in our amination protocols. This ligand provides a remarkably general, efficient, and mild palladium catalyst for aryl iodide amination. Although 3 is slightly air and moisture sensitive, easy procedures can be adopted that avoid the need of a glovebox. Comparisons of the efficacy of 3 in these reactions with that of the proazaphosphatrane P(i-BuNCH2CH2)3N (2) reveal that in addition to the opportunity for transannulation in 2 (but not in 3), other significant stereoelectronic contrasts exist between these two ligands which help account for differences in the activities of the Pd/2 and Pd/3 catalytic systems.
- Urgaonkar, Sameer,Xu, Ju-Hua,Verkade, John G.
-
p. 8416 - 8423
(2007/10/03)
-
- N-aryl substituted tetrahydroquinolines having retinoid agonist, retinoid antagonist or retinoid inverse agonist type biological activity
-
Compounds of the formula STR1 where the symbols have the meaning defined in the specification, have retinoid, retinoid antagonist or retinoid inverse agonist-like biological activity.
- -
-
-