35660-94-7Relevant articles and documents
A BULKY LIGAND AND ITS ORGANOMETALLIC COMPOUND: SYNTHESIS OF HEPTAMETHYLINDENE AND A FERROCENE-TYPE COMPLEX, Fe(η5-C9Me7)2
Miyamoto, T. Ken,Tsutsui, Minoru,Chen, Li-Ban
, p. 729 - 730 (1981)
A bulky new indene, 1-H-1,2,3,4,5,6,7-heptamethylindene, has been synthesized and its application to organometallic chemistry is suggested.
Chemo- and Regioselective Functionalization of Nortrilobolide: Application for Semisynthesis of the Natural Product 2-Acetoxytrilobolide
Doan, Nhu Thi Quynh,Crestey, Fran?ois,Olsen, Carl Erik,Christensen, S?ren Br?gger
, p. 1406 - 1414 (2015)
The difference in reactivity of the hexaoxygenated natural product thapsigargin (1) and the pentaoxygenated nortrilobolide (3) was compared in order to develop a chemo- and regioselective method for the conversion of nortrilobolide (3) into the natural product 2-acetoxytrilobolide (4). For the first time, a stereoselective synthesis of 2-acetoxytrilobolide (4) is described, which involves two key reactions: the first chemical step was a one-pot substitution-oxidation reaction of an allylic ester into its corresponding α,β-unsaturated ketone. The second process consisted of a stereoselective α′-acyloxylation of the key intermediate α,β-unsaturated ketone to afford its corresponding acetoxyketone, which was converted into 2-acetoxytrilobolide (4) in a few steps. This innovative approach would allow the synthesis of a broad library of novel and valuable penta- and hexaoxygenated guaianolides as potential anticancer agents.
Synthesis, characterisation, and polymerisation studies of hexamethylindenyl zirconocenes and hafnocenes
Arnold, Thomas A.Q.,Buffet, Jean-Charles,Turner, Zo? R.,O'Hare, Dermot
, p. 55 - 65 (2015)
Abstract A family of group 4 metallocene complexes based on the hexamethylindenyl ligand (C9Me6H; Ind#) have been prepared and fully characterised. The complexes rac-Ind#2ZrCl2 (rac-1), meso-Ind#2ZrCl2 (meso-1), rac-Ind#2HfCl2 (rac-2), meso-Ind#2HfCl2 (meso-2) were prepared by the reaction of Ind#Li with the corresponding MCl4 (where M = Zr, Hf); and rac-Ind#2Zr(CH2Ph)2 (rac-3) was derived from rac-1 using two equivalents of potassium benzyl (KCH2Ph). All five species were characterised by NMR spectroscopy, single crystal X-ray diffraction and studied using density functional theory. The zirconocenes were tested for their activity as solution-phase ethylene polymerisation catalysts and rac-1 was found to outperform the meso-1 at most temperatures. The benzyl analogue, rac-3, peaked at more than double the activity reported for the dihalide species.
Chemistry of renieramycins. Part 14: Total synthesis of renieramycin i and practical synthesis of cribrostatin 4 (renieramycin H)
Yokoya, Masashi,Kobayashi, Keiichiro,Sato, Mitsuhiro,Saito, Naoki
, p. 4915 - 4933 (2015)
The first total synthesis of (±)-renieramycin I, which was isolated from the Indian bright blue sponge Haliclona cribricutis, is described. The key step is the selenium oxide oxidation of pentacyclic bis-p-quinone derivative (3) stereo- and regioselectively. We also report a large-scale synthesis of cribrostatin 4 (renieramycin H) via the C3-C4 double bond formation in an early stage based on the Avenda?o's protocol, from readily available 1-acetyl-3-(3-methyl-2,4,5-trimethylphenyl)methyl-piperazine-2,5-dione (8) in 18 steps (8.3% overall yield). The synthesis provides unambiguous evidence supporting the original structure of renieramycin I.
Synthetic Studies on Selective, Proapoptotic Isomalabaricane Triterpenoids Aided by Computational Techniques
Boyko, Yaroslav D.,Huck, Christopher J.,Ning, Shang,Shved, Alexander S.,Yang, Cheng,Chu, Tiffany,Tonogai, Emily J.,Hergenrother, Paul J.,Sarlah, David
supporting information, p. 2138 - 2155 (2021/02/09)
The isomalabaricanes comprise a large family of marine triterpenoids with fascinating structures that have been shown to be selective and potent apoptosis inducers in certain cancer cell lines. In this article, we describe the successful total syntheses of the isomalabaricanes stelletin A, stelletin E, and rhabdastrellic acid A, as well as the development of a general strategy to access other natural products within this unique family. High-throughput experimentation and computational chemistry methods were used in this endeavor. A preliminary structure-activity relationship study of stelletin A revealed the trans-syn-trans core motif of the isomalabaricanes to be critical for their cytotoxic activity.
Bromo Radical-Mediated Photoredox Aldehyde Decarbonylation towards Transition-Metal-Free Hydroalkylation of Acrylamides at Room Temperature
Deng, Guo-Jun,Huang, Huawen,Sun, Zhaozhao,Wang, Qiaolin
supporting information, (2021/12/03)
Herein, we report a visible-light-mediated hydroalkylation reaction of alkenes using easily available aldehydes as alkyl sources via bromo radical-promoted photoredox decarbonylation. This protocol provides an alternative entry to C(sp3)?C(sp3) bond formation and features considerable advantages including mild and clean reaction conditions, obviation for transition-metal catalyst, and good functional group compatibility.
Stereospecific Electrophilic Fluorocyclization of α,β-Unsaturated Amides with Selectfluor
Fei, Haiyang,Fu, Yao,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian,Wu, Hongmiao,Xu, Zheyuan,Zhu, Lin
supporting information, (2020/03/30)
An efficient fluorocyclization of α,β-unsaturated amides through a formal halocyclization process is developed. The reaction proceeds under transition-metal-free conditions and leads to the formation of fluorinated oxazolidine-2,4-diones with excellent regio- and diastereoselectivity. The evaluation of the reaction mechanism based on preliminary experiments and density functional theory calculations suggests that a synergetic syn-oxo-fluorination occurs and is followed by an anti-oxo substitution reaction. The reaction opens a new window in the field of stereospecific fluorofunctionalization.
