27816-53-1Relevant academic research and scientific papers
Regioselective 2-alkylation of indoles with α-bromo esters catalyzed by Pd/P,P=O system
Li, Bowen,Tang, Wenjun,Tian, Duanshuai,Tian, Wei
supporting information, (2021/08/13)
A palladium-catalyzed 2-alkylation of indoles with α-bromo esters is developed by employing a P,P=O ligand. The method features excellent regioselectivities, mild reaction conditions, and good functional group compatibility. The employment of the P,P=O ligand as well as 4? molecular sieves were crucial for the success of the transformation. Mechanistic studies indicate the reaction proceed through a radical pathway.
Copper-Catalyzed Synthesis of Indolyl Benzo[b]carbazoles and Their Photoluminescence Property
Hao, Tonggang,Huang, Long,Wei, Yin,Shi, Min
supporting information, p. 5133 - 5137 (2021/07/19)
A copper-catalyzed cascade cyclization of dihydroisobenzofurans with indoles for the rapid construction of indoly benzo[b]carbazoles has been reported, providing the desired products in moderate to good yields under mild conditions along with a broad substrate scope and good functional group tolerance. The photoluminescence property of these indoly benzo[b]carbazoles has also been investigated.
Salicylaldehyde-Promoted Cobalt-Catalyzed C-H/N-H Annulation of Indolyl Amides with Alkynes: Direct Synthesis of a 5-HT3 Receptor Antagonist Analogue
Huang, Mao-Gui,Shi, Shuai,Li, Ming,Liu, Yue-Jin,Liu, Yue-Jin
supporting information, p. 7094 - 7099 (2021/09/14)
A cobalt-catalyzed annulation of the C(sp2)-H/N-H bond of indoloamides with alkynes assisted by 8-aminoquinoline is reported for the synthesis of six-membered indololactams. The use of salicylaldehyde as the ligand is crucial for this transformation. The protocol has a broad scope for both alkynes and indoles. Preparing an active Co complex illustrates that salicylaldehyde plays a key role in the C-H activation step. The synthetic applications are proven by the gram-scale reaction and one-step construction of the multicyclic 5-HT3 receptor antagonist.
Additions of Aldehyde-Derived Radicals and Nucleophilic N-Alkylindoles to Styrenes by Photoredox Catalysis
Klussmann, Martin,Lux, Marcel
supporting information, (2020/04/30)
The consecutive addition of acyl radicals and N-alkylindole nucleophiles to styrenes was established, as well as some additional radical-nucleophile combinations. Both aryl and aliphatic aldehydes give reasonable yields. The reaction proceeds best for α-substituted styrenes, effectively creating a quaternary all-carbon center. Some iridium-based photoredox systems are catalytically active; furthermore, a base is needed in this transformation. Radicals are formed by reductive perester cleavage and hydrogen atom transfer.
Isothiourea-Catalyzed Enantioselective Synthesis of Tetrahydro-α-carbolinones
Liu, Honglei,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information, p. 1301 - 1305 (2020/02/25)
An isothiourea-catalyzed enantioselective annulation protocol using indolin-2-imines with a series of α,β-unsaturated p-nitrophenyl esters for the synthesis of tetrahydro-α-carbolinones was developed. Using 5 mol % of the isothiourea HyperBTM as the Lewis base catalyst, this process allows the enantioselective preparation of a range of C(4)-substituted tetrahydro-α-carbolinones in good to excellent yield and with high enantioselectivity (20 examples, 32-99% yield and up to 99:1 er).
Synthesis of Cyclopenta[b]indoles via a Formal [3+2] Cyclization of N-Sulfonyl-1,2,3-triazoles and Indoles
Duan, Shengguo,Zhang, Wan,Hu, Yuntong,Xu, Ze-Feng,Li, Chuan-Ying
supporting information, p. 3570 - 3575 (2020/08/05)
Annulation of benzoxy-tethered N-sulfonyl-1,2,3-triazoles and indoles has been developed in this paper, providing an efficient and convenient access to valuable cyclopenta[b]indoles in moderate to good yields. α,β-Unsaturated imine, which generated in situ from denitrogenation and 1,2-OBz migration of triazole, provided three carbons for the formal [3+2] cyclization reaction for the first time. (Figure presented.).
Efficient Pd-Catalyzed Direct Coupling of Aryl Chlorides with Alkyllithium Reagents
Dilchert, Katharina,Gessner, Viktoria H.,Gro?johann, Angela,Rodstein, Ilja,Scherpf, Thorsten,Steinert, Henning,Tappen, Jens
supporting information, p. 20596 - 20603 (2020/09/09)
Organolithium compounds are amongst the most important organometallic reagents and frequently used in difficult metallation reactions. However, their direct use in the formation of C?C bonds is less established. Although remarkable advances in the coupling of aryllithium compounds have been achieved, Csp2?Csp3 coupling reactions are very limited. Herein, we report the first general protocol for the coupling or aryl chlorides with alkyllithium reagents. Palladium catalysts based on ylide-substituted phosphines (YPhos) were found to be excellently suited for this transformation giving high selectivities at room temperature with a variety of aryl chlorides without the need for an additional transmetallation reagent. This is demonstrated in gram-scale synthesis including building blocks for materials chemistry and pharmaceutical industry. Furthermore, the direct coupling of aryllithiums as well as Grignard reagents with aryl chlorides was also easily accomplished at room temperature.
Catalytic Aerobic Dehydrogenatin of N-Heterocycles by N-Hydoxyphthalimide
Chen, Weidong,Tang, Hao,Wang, Weilin,Fu, Qiang,Luo, Junfei
supporting information, p. 3905 - 3911 (2020/08/10)
Catalytic methods for the aerobic dehydrogenation of N-heterocycles are reported. In most cases, indoles are accessed efficiently from indolines using catalytic N-hydroxyphthalimide (NHPI) as the sole additive under air. Further studies revealed an improved catalytic system of NHPI and copper for the preparation of other heteroaromatics, for example quinolines. (Figure presented.).
Method for preparing indole compound through air oxidation catalyzed by N-hydroxyphthalimide
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Paragraph 0044-0046, (2020/11/23)
The invention discloses a method for preparing an indole compound through non-transition metal catalyzed air oxidation. According to the method, the low-cost N-hydroxyphthalimide is used as a catalystand air is used as an oxidizing agent, wherein indoline compounds are oxidized in an organic solvent, and synthesis of the indoline compounds is achieved. The method has the advantages of simple reaction operation, low reaction cost, high yield, mild conditions, no heavy metal pollution and the like.
Straightforward access to novel indolo[2,3-: B] indoles via aerobic copper-catalyzed [3+2] annulation of diarylamines and indoles
Gong, Lingzhen,Jiang, Huanfeng,Liang, Taoyuan,Zhang, Min,Zhao, He
supporting information, p. 2807 - 2810 (2020/03/13)
Herein, we report an unprecedented aerobic copper-catalyzed [3+2] annulation reaction of diarylamines with indoles, which allows direct access to novel 2-diarylaminoindolo[2,3-b]indoles, a class of potential photoelectric device molecules. The developed transformation proceeds with broad substrate scope, good functional group tolerance, high chemo-selectivity, and no need for pre-preparation of specific agents, which offers a practical route for diverse and atom-economic synthesis of the desired products that are difficult to prepare with the conventional approaches.
