- Iridium-Catalysed Reductive Deoxygenation of Ketones with Formic Acid as Traceless Hydride Donor
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An iridium-catalysed deoxygenation of ketones and aldehydes is achieved, with formic acid as hydride donor and water as co-solvent. At low catalyst loading, a number of 4-(N,N-disubstituted amino) aryl ketones are readily deoxygenated in excellent yields and chemoselectivity. Numerous functional groups, especially phenolic and alcoholic hydroxyls, secondary amine, carboxylic acid, and alkyl chloride, are well tolerable. Geminally dideuterated alkanes are obtained with up to 90% D incorporation, when DCO2D and D2O are used in place of their hydrogenative counterparts. The activating 4-(N,N-disubstituted amino)aryl groups have been demonstrated to undergo a variety of useful transformations. The deoxygenative deuterations have been used to prepare a deuterated drug molecule Chlorambucil-4,4-d2. (Figure presented.).
- Yang, Zhiheng,Zhu, Xueya,Yang, Shiyi,Cheng, Weiyan,Zhang, Xiaojian,Yang, Zhanhui
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supporting information
p. 5496 - 5505
(2020/10/22)
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- Iridium-Catalyzed Highly Efficient and Site-Selective Deoxygenation of Alcohols
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An iridium-catalyzed, highly efficient, and site-selective deoxygenation of primary, secondary, and tertiary alcohols has been realized, under the assistance of a 4-(N-substituted amino)aryl directing group. Only the hydroxyl adjacent to the directing group can be deoxygenated. The deoxygenation is performed in water, with formic acid as both the promoter and hydride donor. Excellent yields and functionality tolerance, as well as high efficiency (S/C up to 1000 000, TOF up to 445 000 h-1), are obtained. The kinetic isotope effect studies show that hydride formation is the rate-determining step, and the deoxygenation follows an SN1-type pathway. The deoxygenation protocol has been demonstrated useful in the structural modification of naturally occurring ketones and steroids.
- Yang, Shiyi,Tang, Weiping,Yang, Zhanhui,Xu, Jiaxi
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p. 9320 - 9326
(2018/09/21)
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- Metal and acid-free visible light-mediated Friedel-Crafts alkylation reactions of indole with anilines
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Metal and acid-free visible light-induced Friedel-Crafts C3-alkylation reactions of indole derivatives were developed using N,N-dimethylanilines as the carbon source. A cheap and readily available organic dye, Rose Bengal, was applied as the photocatalyst. This environmentally friendly transformation afforded C3-alkylated indoles in moderate to good yields under mild conditions.
- Dai, Xiao-Qiang,Xu, Wen-Xiu,Wen, Ya-Long,Liu, Xing-Hai,Weng, Jian-Quan
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p. 2945 - 2949
(2018/06/29)
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- K 2 S 2 O 8-Mediated Arylmethylation of Indoles with Tertiary Amines via sp 3 C-H Oxidation in Water
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A transition-metal- A nd catalyst-free, highly efficient synthesis of 3-arylmethylindoles has been achieved using tertiary amines as both methylene (-CH 2-) transfer and arylmethylation agents and K 2 S 2 O 8 as a convenient oxidant. The key feature of this protocol is the utilisation of K 2 S 2 O 8 as an inexpensive and easy to handle radical surrogate that can effectively promote the reaction, leading to the formation of C(sp 2)-C(sp 3)-C(sp 2) bonds via sp 3 C-H bond oxidation in water at room temperature in a one-pot procedure.
- Singh, Manjula,Yadav, Arvind K.,Yadav, Lal Dhar S.,Singh, Rana Krishna Pal
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supporting information
p. 2306 - 2310
(2018/10/20)
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- Visible-Light-Promoted Alkylation of Indoles with Tertiary Amines by the Oxidation of a sp3 C-H Bond
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A visible-light driven reaction for the synthesis of 3-arylmethyl indole derivatives using tertiary amines and indoles was first reported. Corresponding products were obtained with yields of up to 70%, and various functional groups on the indoles were well tolerated when Rose Bengal was used as a photosensitizer and air was used as a green oxidant under mild reaction conditions. (Figure presented.).
- Ding, Xuan,Dong, Chun-Lin,Guan, Zhi,He, Yan-Hong
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p. 762 - 767
(2017/12/26)
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- Magnetically separable sulfonic acid catalysed one-pot synthesis of diverse indole derivatives
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Fe3O4-OSO3H was identified as an efficient reusable catalyst for the facile synthesis of diarylmethyl indole derivatives under neat condition by C-C bond forming reaction. Fe3O4-OSO3H catal
- Kothandapani, Jagatheeswaran,Ganesan, Asaithampi,Selva Ganesan, Subramaniapillai
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p. 5568 - 5572
(2015/09/21)
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- PMA-SiO 2-Mediated MCR in PEG-400: A Greener aza-Friedel-Crafts Reaction Leading to 3-Arylmethyl/Diarylmethyl Indoles
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A greener approach for the synthesis of 3-arylmethyl/diarylmethyl indoles has been achieved via a PMA-SiO2-mediated three-component reaction (the aza-Friedel-Crafts reaction) involving indoles, aldehydes, and N,N-disubstituted anilines in PEG-4
- Reddy, Dinne Naresh Kumar,Chandrasekhar, Kothapalli Bannoth,Ganesh, Yaddanapudi Sesha Siva,Gorantla, Srikanth Sharathchandra,Ramanjaneyulu, Siddabathuni,Kumar, K. Shiva,Pal, Manojit
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p. 523 - 533
(2015/10/29)
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- Gold(I)-catalyzed hydroindolylation of allenyl ethers
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The gold(I)-catalyzed reaction/rearrangement of allenyl ethers has been investigated in the presence of indoles. Either hydroindolylation or alkylation of an indole with the pendant group of allenyl ether has been observed. The reaction outcome seems to b
- Kona, Chandrababu Naidu,Shinde, Mahesh H.,Ramana, Chepuri V.
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supporting information
p. 5358 - 5362
(2015/05/20)
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- ZnCl2 promoted efficient, one-pot synthesis of 3-arylmethyl and diarylmethyl indoles
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Anhydrous ZnCl2 mediated convenient, one-pot synthesis of 3-arylmethyl and diarylmethyl indoles was accomplished in good yields. Under reaction condition, in situ formation of kinetically stable bis(indolyl)methane product was identified. Its s
- Subramaniapillai, Selva Ganesan,Ganesan, Asaithampi
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supporting information
p. 694 - 698
(2014/01/23)
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- From waste biomass to solid support: Lignosulfonate as a cost- Effective and renewable supporting material for catalysis
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Lignosulfonate (LS) is an organic waste generated as a byproduct of the cooking process in sulfite pulping in the manufacture of paper. In this paper, LS was used as an anionic supporting material for immobilizing cationic species, which can then be used as heterogeneous catalysts in some organic transformations. With this strategy, three lignin-supported catalysts were prepared including 1) lignin- SO3Sc(OTf)2, 2) lignin-SO3Cu(OTf), and 3) lignin-IL@NH2 (IL= ionic liquid). These solid materials were then examined in many organic transformations. It was finally found that, compared with its homogeneous counterpart as well as some other solid catalysts that are prepared by using different supports with the same metal or catalytically active species, the lignin-supported catalysts showed better performance in these reactions not only in terms of activity but also with regard to recyclability.
- Sun, Shaohuan,Bai, Rongxian,Gu, Yanlong
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supporting information
p. 549 - 558
(2014/04/03)
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- FeCl3 as Lewis acid catalyzed one-pot three-component aza-Friedel-Crafts reactions of indoles, aldehydes, and tertiary aromatic amines
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A new strategy for the synthesis of 3-diarylmethyl indoles was developed through FeCl3 as Lewis acid catalyzed three-component aza-Friedel-Crafts reactions of indoles, aldehydes, and tertiary aromatic amines in one-pot. The reactions generated
- Liu, Jie,He, Tao,Wang, Lei
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experimental part
p. 3420 - 3426
(2011/06/11)
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- Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 CH bond and lewis acid catalysis
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Ruthenium porphyrins (particularly [Ru(2,6-Cl2tpp)CO]; tpp = tetraphenylporphinato) and RuCl3 can act as oxidation and/or Lewis acid catalysts for direct C-3 alkylation of indoles, giving the desired products in high yields (up to 82
- Wang, Ming-Zhong,Zhou, Cong-Ying,Wong, Man-Kin,Che, Chi-Ming
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experimental part
p. 5723 - 5735
(2010/08/20)
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- A novel multi-component reaction of indole, formaldehyde, and tertiary aromatic amines
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A novel multi-component reaction of indoles, formaldehydes, and tertiary aromatic amines is described for the synthesis of dialkylaminoarylated indoles using silica-supported perchloric acid (HClO4-SiO2) as an inexpensive and highly efficient catalyst. The key features of this multi-component reactions are operational simplicity, mild reaction conditions, regioselectivity, and recycling of catalyst.
- Kumar, Atul,Sharma, Siddharth,Maurya, Ram Awatar
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experimental part
p. 5937 - 5940
(2010/01/18)
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- Benzotriazole: A novel synthetic auxiliary
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Benzotriazole and aldehydes react reversibly to give addition products: in the presence of amines and other NH-compounds water can be eliminated to form products of type Bt-CHR-NR′R″. The latter are versatile intermediates for the preparation of primary, secondary, and tertiary amines and in the alkylation of hydroxylamines, hydrazines, amides, thioamides, and sulfonamides. Polyfunctional amines and other polyfunctional compounds can also be prepared, and they enable significant extending of Mannich reaction. Similar oxygen compounds Bt-CRR′-OR″ enable new syntheses of ethers and esters. Reactions in which benzotriazole is eliminated rather than substituted open up new pathways to enamines, enol ethers, and nitrones. The methodology is capable of extension to a variety of vinylogous systems including benzenoid and heteroaromatic derivatives. In addition to acting as a versatile leaving group, benzotriazolyl residues activate neighboring CH bonds to proton loss and a variety of such applications is described.
- Katritzky, Alan R.,Rachwal, Stanislaw,Hitchings, Gregory J.
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p. 2683 - 2732
(2007/10/02)
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- Benzotriazole as a Synthetic Auxiliary: Advantageous Syntheses of Substituted Diarylmethanes and Heterocyclic Analogues
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4-(Benzotriazol-1-ylmethyl)-N,N-dimethylaniline (1b) can be substituted at the CH2 link via lithiation.Both the parent and substituted derivatives react with a variety of electron-rich benzenoid and heteroaromatic compounds in a novel approach to leuco dy
- Katritzky, Alan R.,Lan, Xiangfu,Lam, Jamshed N.
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p. 4397 - 4403
(2007/10/02)
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