901-93-9Relevant academic research and scientific papers
Oxidation of unsaturated steroid ketones with hydrogen peroxide catalyzed by Fe(bpmen)(OTf)2. New methodology to access biologically active steroids by chemo-, and stereoselective processes
Clemente-Tejeda, David,López-Moreno, Alejandro,Bermejo, Francisco A.
, p. 9249 - 9255 (2012)
In this paper we describe a new environmentally friendly method to promote the oxidation of steroids. The chemo- and stereoselective aspects of the oxidation of conjugated enones, dienones, further unsaturated enones, estrone, and cholestane acetates were under study. The great facial stereoselectivity of the method has been shown on substrates 12, 14, and 18 improving some of the updated reported procedures in the literature. Reaction with substrate 16 displays the competition between the C4-C5 and the C9-C11 double bonds. The steric hindrance around C ring activates the C-H hydroxylation at the allylic position on C-12 by formation of the allylic alcohol 17c. The C-H activation at C-5 was proven to succeed on the oxidation reaction of androstane 26 by formation of the tertiary alcohol 27.
Heterocyclic steroids: Synthesis of steroidal selena, tellura, and thia lactones of estrane series
Siddiqui, Abdul U.,Satyanarayana, Yennam,Ahmed, Iqbal,Siddiqui, Abdul H.
, p. 302 - 304 (1996)
A successful approach in the synthesis of 3β-acetoxy-17a-selena-D-homo- 1,3,5(10)-estratrien-17-one (5), 3β-acetoxy-17a-tellura-D-homo-1,3,5(10)- estratrien-17-one (6), and 3β-acetoxy-17a-thia-D-homo-1,3,5(10)-estratrien- 17-one (7) was achieved from 3β-acetoxy-1,3,5(10)-estratrien-17-one (1). The baeyer-Villiger reaction of 3β-acetoxy-1,3,5(10)-estratrien-17-one (1) with perbenzoic acid afforded 3β-acetyxy-17a-oxa-D-homo-1,3,5(10)-estratrien-17- one (2), which on reaction with hydromic acid gave 3β-acetoxy-seco-13- bromo-1,3,5(10)-estratrien-16-oic acid (3). Treatment of bromo acid (3) with thionyl chloride gave 3β-acetovy-seco-13-bromo-1,3,5(10)-estratrien-17 acid chloride (4), whose reaction with Se and Te in the presence of sodium borohydride gave the desired products 5 and 6. Reaction of 3β-acetoxy-seco- 13-bromo-1,3,5(10)-estratrien-17 acid chloride (4) with sodium sulfide gave the thia lactone derivative.
Site-Specific Oxidation of (sp3)C-C(sp3)/H Bonds by NaNO2/HCl
Zhao, Jianyou,Shen, Tong,Sun, Zhihui,Wang, Nengyong,Yang, Le,Wu, Jintao,You, Huichao,Liu, Zhong-Quan
supporting information, p. 4057 - 4061 (2021/05/26)
A site-specific oxidation of (sp3)C-C(sp3) and (sp3)C-H bonds in aryl alkanes by the use of NaNO2/HCl was explored. The method is chemical-oxidant-free, transition-metal-free, uses water as the solvent, and proceeds under mild conditions, making it valuable and attractive to synthetic organic chemistry.
MANGANESE (III) CATALYZED C--H AMINATIONS
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Paragraph 0635; 0769-0770, (2019/04/25)
Reactions that directly install nitrogen into C—H bonds of complex molecules are significant because of their potential to change the chemical and biological properties of a given compound. Selective intramolecular C—H amination reactions that achieve high levels of reactivity, while maintaining excellent site-selectivity and functional-group tolerance is a challenging problem. Herein is reported a manganese perchlorophthalocyanine catalyst [MnIII(ClPc)] for intermolecular benzylic C—H amination of bioactive molecules and natural products that proceeds with unprecedented levels of reactivity and site-selectivity. In the presence of Br?nsted or Lewis acid, the [MnIII(ClPc)]-catalyzed C—H amination demonstrates unique tolerance for tertiary amine, pyridine and benzimidazole functionalities. Mechanistic studies indicate that C—H amination proceeds through an electrophilic metallonitrene intermediate via a stepwise pathway where C—H cleavage is the rate-determining step of the reaction. Collectively these mechanistic features contrast previous base-metal catalyzed C—H aminations.
Photo-Fries Rearrangement of Some 3-Acylestrones in Homogeneous Media: Preparative and Mechanistic Studies
Quindt, Matías I.,Gola, Gabriel F.,Ramirez, Javier A.,Bonesi, Sergio M.
, p. 7051 - 7065 (2019/06/18)
Irradiation of a series of 3-acylestrones under a nitrogen atmosphere in cyclohexane, acetonitrile (MeCN), and methanol (MeOH) was investigated under steady-state conditions. The molecules underwent the photo-Fries rearrangement, with concomitant homolytic fragmentation of the ester group and [1;3]-acyl migration. This pathway afforded the ortho-acyl estrone derivatives, the main photoproducts, together with estrone. During the irradiation of 3-benzoyl estrone, epimerization of estrone through the Norrish type I reaction occurred, providing lumiestrone as the photoproduct. This photoreaction involves the fragmentation of the C-α at the carbonyl group (C-17) of the steroid. On the other hand, epimerization of ortho-regioisomer 2-acetyl estrone occurred during the irradiation of 3-acetyl estrone. Photosensitization with acetone and chemical quenching with N,N,N,N-tetramethyldiazetinedioxide of the photo-Fries reaction confirmed that the photoreaction took place from the singlet excited state while the Norrish type I reaction proceeds efficiently from the triplet excited state. Solvent effects, as well as the nature of the acyl group on the photoreactions, were also studied.
Hydroarylation of Alkenes by Protonation/Friedel-Crafts Trapping: HFIP-Mediated Access to Per-aryl Quaternary Stereocenters
Nielsen, Christian D.-T.,White, Andrew J. P.,Sale, David,Bures, Jordi,Spivey, Alan C.
, p. 14965 - 14973 (2019/11/13)
Upon treatment with a combination of HFIP and an organic sulfonic acid, alkenes behave as Br?nsted bases and protonate to give carbocations which can be trapped by electron-rich arenes. The reaction constitutes a Friedel-Crafts hydroarylation which procee
Protection of COOH and OH groups in acid, base and salt free reactions
Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
supporting information, p. 1444 - 1447 (2018/04/12)
We report an iron-catalyzed general functional group protection method with inexpensive reagents. This environmentally benign process does not use acids or bases, and does not produce waste products. Further purification beyond filtration and evaporation is, in most cases, unnecessary. Free COOH and OH groups can be protected in a one-pot reaction.
Photocatalysis with Quantum Dots and Visible Light: Selective and Efficient Oxidation of Alcohols to Carbonyl Compounds through a Radical Relay Process in Water
Zhao, Lei-Min,Meng, Qing-Yuan,Fan, Xiang-Bing,Ye, Chen,Li, Xu-Bing,Chen, Bin,Ramamurthy, Vaidhyanathan,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 3020 - 3024 (2017/03/13)
Selective oxidation of alcohols to aldehydes/ketones has been achieved with the help of 3-mercaptopropionic acid (MPA)-capped CdSe quantum dot (MPA-CdSe QD) and visible light. Visible-light-prompted electron-transfer reaction initiates the oxidation. The thiyl radical generated from the thiolate anion adsorbed on a CdSe QD plays a key role by abstracting the hydrogen atom from the C?H bond of the alcohol (R1CH(OH)R2). The reaction shows high efficiency, good functional group tolerance, and high site-selectivity in polyhydroxy compounds. The generality and selectivity reported here offer a new opportunity for further applications of QDs in organic transformations.
Identification of Novel Steroidal Androgen Receptor Degrading Agents Inspired by Galeterone 3β-Imidazole Carbamate
Purushottamachar, Puranik,Kwegyir-Afful, Andrew K.,Martin, Marlena S.,Ramamurthy, Vidya P.,Ramalingam, Senthilmurugan,Njar, Vincent C. O.
supporting information, p. 708 - 713 (2016/07/26)
Degradation of all forms of androgen receptors (ARs) is emerging as an advantageous therapeutic paradigm for the effective treatment of prostate cancer. In continuation of our program to identify and develop improved efficacious novel small-molecule agents designed to disrupt AR signaling through enhanced AR degradation, we have designed, synthesized, and evaluated novel C-3 modified analogues of our phase 3 clinical agent, galeterone (5). Concerns of potential in vivo stability of our recently discovered more efficacious galeterone 3β-imidazole carbamate (6) led to the design and synthesis of new steroidal compounds. Two of the 11 compounds, 3β-pyridyl ether (8) and 3β-imidazole (17) with antiproliferative GI50 values of 3.24 and 2.54 μM against CWR22Rv1 prostate cancer cell, are 2.75- and 3.5-fold superior to 5. In addition, compounds 8 and 17 possess improved (～4-fold) AR-V7 degrading activities. Importantly, these two compounds are expected to be metabolically stable, making them suitable for further development as new therapeutics against all forms of prostate cancer.
NONSTEROIDAL AND STEROIDAL COMPOUNDS WITH POTENT ANDROGEN RECEPTOR DOWN-REGULATION AND ANTI PROSTATE CANCER ACTIVITY
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Page/Page column 53, (2014/10/18)
Nonsteroid and steroid compounds that cause down-regulation of the androgen receptor (AR), both full length and splice variant, induce apoptosis and inhibit proliferation of inhibiting proliferation and migration of androgen sensitive cancer cells. The steroid compounds and nonsteroid compounds may be agents for the prevention and/or treatment of cancer, including prostate cancer, castration resistant prostate cancer, bladder cancer, pancreatic cancer, hepatocellular carcinoma, benign prostatic hyperplasia (BPH), Kennedy's disease, androgenetic alopecia, breast cancer, androgen-insensitive syndrome, and spinal and bulbar muscular atrophy.
