66377-68-2Relevant academic research and scientific papers
Intermolecular Conjugate Addition of Pyrroloindoline and Furoindoline Radicals to α,β-Unsaturated Enones via Photoredox Catalysis
Zhou, Shupeng,Zhang, Deliang,Sun, Yu,Li, Ruofan,Zhang, Wenhao,Li, Ang
, p. 2867 - 2872 (2014)
We have developed an intermolecular conjugate addition of 3a-pyrroloindoline/furoindoline radicals to α,β-unsaturated enones, through visible-light photoredox catalysis. Ir(ppy)2(dtbbpy) PF6 was found to be an effective promoter to initiate this reaction from readily available 3a-bromopyrroloindolines/furoindolines. This method was exploited to prepare a series of indole terpenoid-like compounds of potential biological interest.
Fenton chemistry enables the catalytic oxidative rearrangement of indoles using hydrogen peroxide
Zhao, Guodong,Liang, Lixin,Wang, Eryu,Lou, Shaoyan,Qi, Rui,Tong, Rongbiao
supporting information, p. 2300 - 2307 (2021/04/12)
Oxidative rearrangement of indoles is an important transformation to yield 2-oxindoles and spirooxindoles, which are present in many pharmaceutical agents and bioactive natural products. Previous oxidation methods show either broad applicability or greenness but rarely achieve both. Reported is the discovery of Fenton chemistry-enabled green catalytic oxidative rearrangement of indoles, which has wide substrate scope (42 examples) and greenness (water as the only stoichiometric byproduct) at the same time. Detailed mechanistic studies revealed that the Fenton chemistry generated hydroxyl radicals that further oxidize bromide to reactive brominating species (RBS: bromine or hypobromous acid). Thisin situgenerated RBS is the real catalyst for the oxidative rearrangement. Importantly, the RBS is generated under neutral conditions, which addresses a long-lasting problem of many haloperoxidase mimics that require a strong acid for the oxidation of bromide with hydrogen peroxide. It is expected that this new catalytic Fenton-halide system will find wide applications in organic synthesis.
Synthesis and Antibacterial Activity of Calycanthaceous Alkaloid Derivatives
Zheng, Shaojun,Gu, Yongdong,Zhu, Rui,Li, Longbo,Bai, Hongjin,Zhang, Jiwen
, p. 127 - 130 (2018/02/19)
A series of 45 calycanthaceous alkaloid derivatives with the tetrahydropyrroloindole core structure was synthesized from tryptophan in good yields. The synthesized compounds were evaluated against five strains of bacteria (Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coil, Ralstonia solanacearum, and Pseudomonas aeruginosa). The bioassays indicated that among the synthesized compounds, compounds b3 and b4 exhibited a high degree of activity towards Gram positive B. subtilis. Compounds a14 and a18 displayed a high degree of activity towards R. solanacearum. These results will pave the way for further design, structural modification, and development of calycanthaceous alkaloids as antibacterial agents.
Synthesis and fungicidal activity of tryptophan analogues–the unexpected calycanthaceous alkaloid derivatives
Zheng, Shaojun,Gu, Yongdong,Li, Longbo,Zhu, Rui,Cai, Xingwei,Bai, Hongjin,Zhang, Jiwen
, p. 1142 - 1149 (2017/02/26)
A series of 21?N-protected tryptophan derivatives were synthesised from tryptophan in good yields. Their structures were characterised by IR,1H NMR,13C NMR, DEPT (90° and 135°) and MS analysis. The synthesised compounds were evaluated against a wide variety of plant pathogen fungi. Compounds a19 and a21 displayed activity against Fusarium oxysporum (F. oxysporum), and compound a21 showed high activity against F. oxysporum and Eggplant Verticillium, with EC50values of 58.27 and 77.39?μg?mL?1, respectively. Considering that the bioassay of the title compounds was evaluated, effects of the chain alkyl substituents may contribute to the significant variations in fungicidal potency. Their structure–antifungal activity relationships were also discussed. These results will pave the way for further design, structural modification and development of calycanthaceous alkaloids as antimicrobial agents.
Synthesis of tryptophans by Lewis acid promoted ring-opening of aziridine-2-carboxylates: Optimization of protecting group and Lewis acid
Tirotta, Ilaria,Fifer, Nathan L.,Eakins, Julia,Hutton, Craig A.
, p. 618 - 620 (2013/02/23)
The preparation of tryptophan derivatives through the Lewis acid promoted substitution of aziridine carboxylates with indole was found to be accompanied by a ring-expansion reaction to generate an oxazolidinone byproduct. The ratio of tryptophan to oxazol
Orthogonal protecting groups in the synthesis of tryptophanyl- hexahydropyrroloindoles
Ruiz-Sanchis, Pau,Savina, Svetlana A.,Acosta, Gerardo A.,Albericio, Fernando,Alvarez, Mercedes
supporting information; experimental part, p. 67 - 73 (2012/01/15)
The synthesis of various polycyclic systems containing aC 3a-Ni bond between a hexahydropyrrolo[2,3-b]indole and an indole tryptophan is described here. A series of experiments were performed to determine the best combination of five orthogonal protecting groups and the best reaction conditions for formation of said bond, which is a common feature among many recently discovered marine natural products.
Total synthesis of nominal (11S)- and (11R)-cyclocinamide A
Garcia, Jessica M.,Curzon, Stephanie S.,Watts, Katharine R.,Konopelski, Joseph P.
supporting information; experimental part, p. 2054 - 2057 (2012/06/29)
The cyclocinamides possess a unique β2αβ 2α 14-membered tetrapeptide core. The initially reported biological data and intriguing structure, which was without full stereochemical identification, necessitated synthesis of both nominal (all-S) cyclocinamide A and the 11R isomer. The completed synthesis is highlighted by the use of a (cyclo)asparagine-containing dipeptide as a turn inducing fragment. Due to inconsistencies in analytical data between natural and synthetic samples, a re-evaluation of the natural product stereochemistry appears necessary.
Total Synthesis of (+)-Decursivine
Sun, Deqian,Zhao, Qiwu,Li, Chaozhong
supporting information; experimental part, p. 5302 - 5305 (2011/12/15)
The first asymmetric synthesis of natural indole alkaloid (+)-decursivine was accomplished. The key step involves the PIFA-mediated intramolecular [3 + 2] cycloaddition of 5-hydroxytryptophan with a substituted cinnamamide in a highly diastereoselective m
A contribution to the elucidation of the biosynthesis of 3-chloro-4-(3′-chloro-2′-nitrophenyl)-1H-pyrrole (pyrrolnitrin)
Vázquez, Ana Bertha,Bernès, Sylvain,Ortíz, Aurelio,Quintero, Leticia,Meza-León, Rosa L.
scheme or table, p. 1539 - 1541 (2009/06/18)
Selective openings of the ring B of the derivative hexapyrroloindol in basic conditions confirm the rearrangement of the tryptophan to aminoarylpyrrol, analogously to the step catalyzed by the enzyme prnB in the biosynthesis of pyrrolnitrin.
The first method for protection-deprotection of the indole 2,3-π bond
Baran, Phil S.,Guerrero, Carlos A.,Corey
, p. 1999 - 2001 (2007/10/03)
(Matrix presented) The scope and generality of a new reaction of indoles with MTAD is discussed. In most cases the ene-type reaction proceeds within seconds or minutes at 0°C to provide the urazole adducts in high yield. This reaction provides the first method for protecting the indole 2,3-double bond since the urazole adducts can be reconverted to the starting indole (retro-ene) simply by heating.
