- Enantioselective Construction of Spirooxindole-Fused Cyclopentanes
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The present study reports an asymmetric organocatalytic cascade reaction of oxindole derivates with α,β-unsaturated aldehydes efficiently catalyzed by simple chiral secondary amine. Spirooxindole-fused cyclopentanes were produced in excellent isolated yields (up to 98%) with excellent enantiopurities (up to 99% ee) and moderate to high diastereoselectivities. The synthetic utility of the protocol was exemplified on a set of additional transformations of the corresponding spiro compounds. In addition, a study showing the promising biological activity of selected enantioenriched products was accomplished.
- Do?ekal, Vojtěch,Vopálenská, Andrea,Měrka, Pavel,Kone?ná, Klára,Jand'Ourek, Ond?ej,Pour, Milan,Císa?ová, Ivana,Vesely, Jan
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p. 12623 - 12643
(2021/07/31)
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- Au(I)-Catalyzed Domino Cyclization of 1,6-Diynes Incorporated with Indole
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We disclose herein a Au(I)-catalyzed domino cyclization of 1,6-diynes incorporated with indole. This protocol enabled the diastereoselective buildup of indole-fused azabicyclo[3.3.1]nonanes from linear precursors. Density functional theory calculations showed that the reaction proceeded via an unprecedented cascade dearomatization/rearomatization/dearomatization process. Independent gradient model analysis revealed that a noncovalent attractive interaction between the distal alkyne and the Au/proximal complex was responsible for the chemoselectivity of the first spirocyclization step.
- Chen, Guzhou,Liu, Peng-Yu,Zou, Huanhuan,Hu, Jiadong,Fang, Xiaowu,Xu, Dongyang,He, Yu-Peng,Wei, Hongbo,Xie, Weiqing
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supporting information
p. 2279 - 2284
(2021/04/05)
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- Development of the Vinylogous Pictet–Spengler Cyclization and Total Synthesis of (±)-Lundurine A
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A novel vinylogous Pictet–Spengler cyclization has been developed for the generation of indole-annulated medium-sized rings. The method enables the synthesis of tetrahydroazocinoindoles with a fully substituted carbon center, a prevalent structural motif in many biologically active alkaloids. The strategy has been applied to the total synthesis of (±)-lundurine A.
- Nash, Aaron,Qi, Xiangbing,Maity, Pradip,Owens, Kyle,Tambar, Uttam K.
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supporting information
p. 6888 - 6891
(2018/05/08)
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- Palladium-Catalyzed Asymmetric Allylic Alkylation of 3-Substituted 1 H-Indoles and Tryptophan Derivatives with Vinylcyclopropanes
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Vinylcyclopropanes (VCPs) are known to generate 1,3-dipoles with a palladium catalyst that initially serve as nucleophiles to undergo [3 + 2] cycloadditions with electron-deficient olefins. In this report, we reverse this reactivity and drive the 1,3-dipoles to serve as electrophiles by employing 3-alkylated indoles as nucleophiles. This represents the first use of VCPs for the completely atom-economic functionalization of 3-substituted 1H-indoles and tryptophan derivatives via a Pd-catalyzed asymmetric allylic alkylation (Pd-AAA). Excellent yields and high chemo-, regio-, and enantioselectivities have been realized, providing various indolenine and indoline products. The method is amenable to gram scale and works efficiently with tryptophan derivatives that contain a diketopiperazine or diketomorpholine ring, allowing us to synthesize mollenine A in a rapid and ligand-controlled fashion. The obtained indolenine products bear an imine, an internal olefin, and a malonate motif, giving multiple sites with diverse reactivities for product diversification. Complicated polycyclic skeletons can be conveniently constructed by leveraging this unique juxtaposition of functional groups.
- Trost, Barry M.,Bai, Wen-Ju,Hohn, Christoph,Bai, Yu,Cregg, James J.
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supporting information
p. 6710 - 6717
(2018/05/24)
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- A Photoredox-Induced Stereoselective Dearomative Radical (4+2)-Cyclization/1,4-Addition Cascade for the Synthesis of Highly Functionalized Hexahydro-1H-carbazoles
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A stereoselective synthesis of functionalized hexahydrocarbazoles was developed based on an unprecedented photoredox-induced dearomative radical (4+2)-cyclization/1,4-addition cascade between 3-(2-iodoethyl)indoles and acceptor-substituted alkenes. The title reaction simultaneously generates three C?C bonds and one C?H bond, along with three contiguous stereogenic centers. The hexahydro-1H-carbazole products are highly valuable intermediates for the synthesis of novel antibiotics, as well as unnatural ring homologues of polycyclic indoline alkaloids.
- Alpers, Dirk,Gallhof, Malte,Witt, Julian,Hoffmann, Frank,Brasholz, Malte
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supporting information
p. 1402 - 1406
(2017/01/24)
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- Aqueous Titanium Trichloride Promoted Reductive Cyclization of o-Nitrostyrenes to Indoles: Development and Application to the Synthesis of Rizatriptan and Aspidospermidine
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Treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-H amination process. A range of functions such as halides (Cl, Br), carbonyl (ester, carbamate), cyano, hydroxy, and amino groups were tolerated. From β,β-disubstituted o-nitrostyrenes, 2,3-disubstituted indoles were formed by a domino reduction/cyclization/migration process. Mild conditions, simple experimental procedure, ready accessibility of the starting materials and good to excellent yields characterize the present transformation. The methodology was used as a key step in a concise synthesis of rizatriptan and a formal total synthesis of aspidospermidine. Mild and efficient treatment of o-nitrostyrenes with aqueous TiCl3 solution at room temperature afforded indoles through a formal reductive C(sp2)-Hamination process. A concise synthesis of a marketed drug (rizatriptan) and a formal total synthesis of aspidospermidine featuring this novel N-heterocyclization process are reported.
- Tong, Shuo,Xu, Zhengren,Mamboury, Mathias,Wang, Qian,Zhu, Jieping
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p. 11809 - 11812
(2015/10/05)
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- Dearomatization of tryptophols via a vanadium-catalyzed asymmetric epoxidation and ring-opening cascade
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An enantioselective epoxidation of tryptophols followed by an intramolecular epoxide opening reaction was realized by chiral vanadium catalysts derived from C2 symmetric bis-hydroxamic acid (BHA) ligands. 3a-Hydroxyfuroindoline derivatives with up to 89% yield and 90% ee were obtained under mild reaction conditions.
- Han, Long,Liu, Chuan,Zhang, Wei,Shi, Xiao-Xin,You, Shu-Li
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supporting information
p. 1231 - 1233
(2014/02/14)
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- Synthesis and evaluation of novel 2,3-dihydrobenzo[b][1,4]dioxin- and indolealkylamine derivatives as potential antidepressants
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A series of 2,3-dihydrobenzo[b][1,4]dioxin- and indolealkylamine derivatives were synthesized and the target compounds were evaluated for their binding affinities at the 5-HT1A receptor and serotonin transporter. Antidepressant-like activities of the compounds were screened using the tail suspension and forced swim tests in mice. Preliminary results indicated that the target compounds exhibited high binding affinities at the 5-HT1A receptor and serotonin transporter, and produced marked antidepressant-like effects. The best example from this study, compound 5, exhibited high binding affinities for the 5-HT1A receptor (Ki = 96 nM) and serotonin transporter (Ki = 9.8 nM). The intrinsic activity of compound 5 showed agonistic property to the 5-HT1A receptor and inhibition of the 5-HT transporter. Furthermore, compound 5 exhibited greater antidepressant efficacy than fluoxetine and showed acceptable pharmacokinetic properties. A series of 3-(2-(4-((2,3-dihydrobenzo[b][1,4]dioxin-3-yl)methyl) piperazin-1-yl)ethyl-1H-indole derivatives were synthesized and the target compounds were evaluated for their antidepressant activities in vitro and in vivo. The compounds described were also evaluated for dual 5-HTT and 5-HT 1A receptor activities.
- Liu, Xin,Wang, Songlin,Chen, Yin,Liu, Xinghua,Xu, Xiangqing,Liu, Bi-Feng,Zhang, Guisen
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- Larock heteroannulation of 2-bromoanilines with internal alkynes via ligand and salt free Pd/C catalysed reaction
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An alternative to the use of ligands and homogeneous catalysis to promote the synthesis of 2,3-disubstituted indoles starting from 2-bromoanilines is described for the first time. This reaction could be achieved through a Larock heteroannulation via a ligand free heterogeneous catalysis.
- Batail, Nelly,Dufaud, Véronique,Djakovitch, Laurent
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experimental part
p. 1916 - 1918
(2011/04/22)
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- SUBSTITUTED INDOLE DERIVATIVES
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Provided herein are indole derivatives, pharmaceutical compositions containing them, methods for their use, and methods for preparing these compounds.
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Page/Page column 75-76
(2008/06/13)
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- A novel substitution reaction of tetrahydropyrano[3,4-b]indole derivative - Chain extension and structural correlation study
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An unusual cyanation with rearrangement of a 1-chloromethyl-tetrahydropyrano[3,4-b]indole-1-acetic acid ester derivative is reported. The resulting C-1 chain extension product is identified by correlation studies and spectral method.
- Chou, Shan-Yen
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p. 1095 - 1110
(2007/10/03)
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