- 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
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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.
- Clemente-Tejeda, David,López-Moreno, Alejandro,Bermejo, Francisco A.
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- Heterocyclic steroids: Synthesis of steroidal selena, tellura, and thia lactones of estrane series
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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.
- Siddiqui, Abdul U.,Satyanarayana, Yennam,Ahmed, Iqbal,Siddiqui, Abdul H.
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- Site-Specific Oxidation of (sp3)C-C(sp3)/H Bonds by NaNO2/HCl
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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.
- Zhao, Jianyou,Shen, Tong,Sun, Zhihui,Wang, Nengyong,Yang, Le,Wu, Jintao,You, Huichao,Liu, Zhong-Quan
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supporting information
p. 4057 - 4061
(2021/05/26)
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- MANGANESE (III) CATALYZED C--H AMINATIONS
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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.
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Paragraph 0635; 0769-0770
(2019/04/25)
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- Photo-Fries Rearrangement of Some 3-Acylestrones in Homogeneous Media: Preparative and Mechanistic Studies
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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.
- Quindt, Matías I.,Gola, Gabriel F.,Ramirez, Javier A.,Bonesi, Sergio M.
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p. 7051 - 7065
(2019/06/18)
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- Hydroarylation of Alkenes by Protonation/Friedel-Crafts Trapping: HFIP-Mediated Access to Per-aryl Quaternary Stereocenters
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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
- Nielsen, Christian D.-T.,White, Andrew J. P.,Sale, David,Bures, Jordi,Spivey, Alan C.
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p. 14965 - 14973
(2019/11/13)
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- Protection of COOH and OH groups in acid, base and salt free reactions
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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.
- Zhu, Xiaotao,Qian, Bo,Wei, Rongbiao,Huang, Jian-Dong,Bao, Hongli
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supporting information
p. 1444 - 1447
(2018/04/12)
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- Photocatalysis with Quantum Dots and Visible Light: Selective and Efficient Oxidation of Alcohols to Carbonyl Compounds through a Radical Relay Process in Water
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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.
- Zhao, Lei-Min,Meng, Qing-Yuan,Fan, Xiang-Bing,Ye, Chen,Li, Xu-Bing,Chen, Bin,Ramamurthy, Vaidhyanathan,Tung, Chen-Ho,Wu, Li-Zhu
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supporting information
p. 3020 - 3024
(2017/03/13)
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- Identification of Novel Steroidal Androgen Receptor Degrading Agents Inspired by Galeterone 3β-Imidazole Carbamate
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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.
- Purushottamachar, Puranik,Kwegyir-Afful, Andrew K.,Martin, Marlena S.,Ramamurthy, Vidya P.,Ramalingam, Senthilmurugan,Njar, Vincent C. O.
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supporting information
p. 708 - 713
(2016/07/26)
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- NONSTEROIDAL AND STEROIDAL COMPOUNDS WITH POTENT ANDROGEN RECEPTOR DOWN-REGULATION AND ANTI PROSTATE CANCER ACTIVITY
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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.
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- Synthesis and evaluation of analogues of estrone-3-O-sulfamate as potent steroid sulfatase inhibitors
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Estrone sulfamate (EMATE) is a potent irreversible inhibitor of steroid sulfatase (STS). In order to further expand SAR, the compound was substituted at the 2- and/or 4-positions and its 17-carbonyl group was also removed. The following general order of p
- Lawrence Woo,Leblond, Bertrand,Purohit, Atul,Potter, Barry V.L.
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scheme or table
p. 2506 - 2519
(2012/06/01)
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- Sequential pericyclic reaction of ene-diallene: synthesis of (±)-estrone
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The one-pot construction of perhydrophenanthrene from an acyclic substrate was achieved via a sequential pericyclic reaction, which involved the in situ generation of ene-diallene species due to Myers' propargyl alcohol-allene transformation. The resulting perhydrophenanthrene derivative could be successfully converted into (±)-estrone.
- Hakuba, Hirohumi,Kitagaki, Shinji,Mukai, Chisato
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p. 12639 - 12645
(2008/03/14)
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- Molecular iodine in isopropenyl acetate (IPA): a highly efficient catalyst for the acetylation of alcohols, amines and phenols under solvent free conditions
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Iodine in isopropenyl acetate (IPA) is a highly efficient catalyst for the acetylation of a variety of alcohols, phenols and amines under solvent free conditions. Primary, secondary, tertiary alcohols, amines and mono to polyhydroxy phenols and anilines with electron donating or withdrawing substituents can be easily acetylated in good to excellent yield at 85-90 °C.
- Ahmed, Naseem,van Lier, Johan E.
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p. 5345 - 5349
(2007/10/03)
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- COMPOUND
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There is provided a compound of Formula (I) wherein (I) R is a selected from (i) an alkyloxyalkyl group (ii) a nitrile group, and wherein R is capable of forming a hydrogen bond (iii) alkylaryl group, wherein the aryl group is substituted by other than a C1-10 group (iv) alkenylaryl group wherein the aryl group is substituted (v) alkyiheteroaryl group, wherein when heteroaryl group comprises only C and N in the ring, the aryl group is substituted by other than a methyl group (vi) alkenylheteroaryl group, (vii) =N-O-alkyl or =N-O-H group (viii) branched alkenyl (ix) alkyl-alcohol group (x) amide or alkylamide wherein (a) the alkyl of the alkylamide is - CH2- or -CH2CH2-, (b) the amide is di-substituted and/or (c) the amide is substituted with at least one of a I kyl heterocycle group, al ke nyl heterocycle group, alkylheteroaryl group, alkenylheteroaryl group, heteroaryl group, alkylamine group, alkyloxyalkyl group, alkylaryl group, straight or branched alkyl group, (xi) -CHO so that R, together with R3 provide the enol tautomer (a); OR R1 together with R form (xii) a pyrazole wherein (a) R is =N-0-alkyl or =N-0-H group, (b) the pyrazole is substituted with one of alkyl-OH group, alkyl ester group, alkyloxyalkyl. group, branched alkyl group, and an amide and/or (c) the 2 position is substituted with a group selected from -OH and -0-hydrocarbyl (xiii) a heteroaryl ring to provide a compound of the formula (b); (II) Ris selected from groups capable of forming a hydrogen bond, a sulphamate group, a phosphonate group, a thiophosphonate group, a sulphonate group and a sulphonamide group; and (III) Ris selected from -OH, =O, or a -C(=O)- mimetic.
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Page 167-168
(2010/02/08)
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- Halogenated sulphamate-, phosphonate-, thiophosphonate-, sulphonate- and sulphonamide- compounds as inhibitors of steroid sulphatase
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A compound is described. The compound has the formula (Ia) as presented in the FIG. 1; wherein: X is a ring having at least 4 atoms in the ring; K is hydrocarbyl group; Rh1 is an optional halo group; Rh2 is an optional halo group; at least one of Rh1 and Rh2 is present; Rs is any one of a sulphamate group, a phosphonate group, a thiophosphonate group, a sulphonate group or a sulphonamide group. The compound is capable of inhibiting steroid sulphatase (STS) activity.
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- Chemoselective construction of novel steroid derivatives.
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Alpha-halo-alpha-heteroarylalkyllithiums, generated by deprotonation of the corresponding halides, when added promptly to steroids with C=O or C=NR groups, lead to epoxides and aziridines. The reactions are regio- and stereoselective; in fact, in the presence of more than one C=O group, the oxido or aziridino functions are formed uniquely at the C=O of C-17 (or C-20 depending on its position in the starting molecule), and the C-20(R) stereoisomer is often the only product isolated. Protection of the hydroxyl group present on several considered steroids was required, and it was accomplished through derivatization in acetyl, ether, or lactone.
- Troisi, Luigino,Florio, Saverio,Granito, Catia
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p. 687 - 693
(2007/10/03)
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- Aerobic deprotection of monothioacetals catalyzed by trichlorooxyvanadium
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Monothioacetals are easily deprotected into carbonyls using a catalytic amount of trichlorooxyvanadium under an oxygen atmosphere.
- Kirihara, Masayuki,Ochiai, Yuta,Arai, Nobuka,Takizawa, Shinobu,Momose, Takefumi,Nemoto, Hideo
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p. 9055 - 9057
(2007/10/03)
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- The behaviour of some estrogens in nitration process: I. Estrone nitration with NaNO2 in the presence of crown ethers
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Estrone 1 was nitrated in methylene chloride with sodium azotite (NaNO2, in solid state or solved in water) in the presence of crown ethers CE (12-crown-4, 15-crown-5, 18-crown-6, dicyclohexyl-18-crown-6) yielding two isomere 2 and 3. Estrone 1 conversion in 2 and 3 nitroderivatives was 3-64%, depending on reactants ratio (1: NaNO2:CE), CE type, reaction time and biphasic system. The nitroisomers ratio was 2:3 > 1 depending on reaction conditions. The process is of autocatalysis type as results from the HNO2 formed in an acid (1)-base (NO2-) reaction catalysed by CE (which transfer the NO2- anion in the organic phase).
- Luca, Constantin,Nourescu, Dana,Cǎproiu, Miron T.,Pencu, Gabriela I.,Constantinescu, Titus
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p. 855 - 860
(2007/10/03)
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- Tetrapropylammonium perruthenate as a mild and efficient oxidant for sensitive steroidal alcohols
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Tetrapropylammonium perruthenate N-methylmorpholine N-oxide oxidation of steroidal alcohols is described. The reagent combination is mild and gave good yields of the corresponding ketones. Although the oxidation can generate ketones from 3-, 11-, 15-, 17-, and 20-hydroxy steroids, the oxidation of homoallylic alcohols proceeds in low yields. Finally, we observed that the oxidation reagents will convert 17α-hydroxy-2-keto steroids to 17-keto systems in excellent yields.
- Acosta, C. Kirk,Rao, Pemmaraju N.,Kim, Hyun K.
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p. 205 - 208
(2007/10/02)
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- Efficient regioselective a-ring functionalization of oestrogens
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Complete series of 2-halo- and 2-cyano-oestrogens have been prepared in good to high yields: 2-chloro, 2-bromo, 2-iodo, and 2-cyano derivatives via oestrogen-thallium (III) bis(trifluoroacetate) intermediates, and 2- and 4- fluorooestrogens by direct functionalization using N-fluoropyridinium triflate.
- Bulman Page, Philip C.,Hussain, Fazal,Maggs Paul Morgan, James L.,Kevin Park
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p. 2059 - 2068
(2007/10/02)
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- Applications of 1-Alkoxycarbonyl- and 1-Acyl-v-triazolopyridines as Acylating Reagents
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Selective N-protection of hydroxyamino esters has been readily achieved using 1-alkoxycarbonyl- or 1-acyl-v-triazolopyridines.The amide-type triazolides reacted with alcohols in the presence of DBU at room temperature to afford in high yields the corresponding esters.The different reactivity of 1- and 3-alkoxycarbonyl derivatives of the title bicyclic system toward primary amines has been further investigated.
- Torrini, Ines,Zecchini, Giampiero Pagani,Agrosi, Francesco,Paradisi, Mario Paglialunga
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p. 1459 - 1463
(2007/10/02)
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- INFLUENCE OF A SUBSTITUENT AT C3 ON THE DIRECTION OF BROMINATION OF ESTRA-1,3,5(10)TRIEN-17-ONES
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The influence of a C3 substituent on the direction of bromination of estra-1,3,5(10)-trien-17-one is discussed: Estrone and its methyl ether give mainly derivatives bromine-substituted in ring A, while the bromination of estrone acetate leads to the production of 16-mono-and 16,16,dibromo-substituted estrones.
- Fedorova, O. I.,Morozova, L. S.,Alekseeva, L. M.,Grinenko, G. S.
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p. 305 - 308
(2007/10/02)
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- PREPARATION OF 16-SUBSTITUTED 3-HYDROXYESTRA-1,3,5(10)-TRIENE-17-ONE STARTING WITH THE BROMINATION OF ESTRONE ACETATE
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The bromination of estrone acetate (Ia) leads to a mixture of acetates of 16α-bromo-16β-bromo-, and 16,16-dibromoestrone (IIa, IIIa, and IVa) in a ratio of 63:28:9.On treatment with an aqueous methanolic solution of potash, depending on the conditions, a mixture of (IIa) and (IIIa) gives 3,16α-dihydroxyestra-1,3,5(10)-trien-17-one (V) or 3,17β-dihydroxyestra-1,3,5(10)-trien-16-one (VI).When 5 g of (Ia) was brominated with 2.8 g of Br2 in chloroform and the products were chromatographed on silica gel, 0.36 g of (IVa), C20H22Br2O3, mp 165-166 deg C (from ether) 0.37 g of (IIIa), mp 169-170.5 deg C, 4.6 g of a mixture of (IIa) and (IIIa), 30 mg of (Ia) and 0.2 g of a mixture of 16α- and 16β-bromoestrones was obtained.The action of potash on a mixture of (IIa) and (IIIa) in aqueous MeOH at 20 deg C led to the epimerization of the (IIa) into (IIIa) and then the conversion of the latter into (V) with mp 203.5-206 deg C; diacetate with mp 172-173 deg C (acetone-ethanol).Similarly, but with heating (98 deg C, 3 h), a mixture of (IIa) and (IIIa) was converted into (VI), with mp 234-236 deg C.Characteristics of the IR and PMR spectra of the compounds obtained are given.
- Fedorova, O. I.,Morozova, L. S.,Alekseeva, L. M.,Grinenko, G. S.
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p. 437 - 440
(2007/10/02)
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