- Stepwise benzylic oxygenation via uranyl-photocatalysis
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Stepwise oxygenation at the benzylic position (1°, 2°, 3°) of aromatic molecules was comprehensively established under ambient conditions via uranyl photocatalysis to produce carboxylic acids, ketones, and alcohols, respectively. The accuracy of the stepwise oxygenation was ensured by the tunability of catalytic activity in uranyl photocatalysis, which was adjusted by solvents and additives demonstrated through Stern–Volmer analysis. Hydrogen atom transfer between the benzylic position and the uranyl catalyst facilitated oxygenation, further confirmed by kinetic studies. Considerably improved efficiency of flow operation demonstrated the potential for industrial synthetic application.
- Hu, Deqing,Jiang, Xuefeng
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supporting information
p. 124 - 129
(2022/01/19)
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- One-Pot C-H Arylation/Lactamization Cascade Reaction of Free Benzylamines
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An efficient method has been developed for the synthesis of seven-membered biaryl lactams involving Pd-catalyzed, native amine-directed, ortho-arylation of benzylamines followed by in situ lactamization. This cascade sequence is enabled by the use of 2-iodobenzoates, which facilitates C-H arylation from the free amine under conditions that typically require an improved directing group approach. This reaction is characterized by a broad substrate scope with good functional group tolerance. The need for an ester versus carboxylic acid-functionalized coupling partner is also explored, as is the potential for synthesizing eight-membered biaryl lactams. Various applications are also investigated, including access to the aza-brassinolide core.
- Chand-Thakuri, Pratibha,Landge, Vinod G.,Kapoor, Mohit,Young, Michael C.
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supporting information
p. 6626 - 6644
(2020/07/14)
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- Synthesis of 4H-1,3-Benzoxazines via Metal- and Oxidizing Reagent-Free Aromatic C-H Oxygenation
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An unprecedented electrochemical aromatic C-H oxygenation reaction for the synthesis of 4H-1,3-benzoxazines from easily available N-benzylamides is reported. These oxidative cyclization reactions proceed in a transition metal- and oxidizing reagent-free fashion and produce H2 as only theoretical byproduct. Adapting the C-H oxygenation reaction in an electrochemical microreactor has been demonstrated.
- Xu, Fan,Qian, Xiang-Yang,Li, Yan-Jie,Xu, Hai-Chao
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supporting information
p. 6332 - 6335
(2017/12/08)
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- Evaluation of adenine as scaffold for the development of novel P2X3 receptor antagonists
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Ligands that selectively block P2X3 receptors localized on nociceptive sensory fibres may be useful for the treatment of chronic pain conditions including neuropathic pain, migraine, and inflammatory pain. With the aim at exploring the suitability of aden
- Lambertucci, Catia,Sundukova, Mayya,Kachare, Dhuldeo D.,Panmand, Deepak S.,Dal Ben, Diego,Buccioni, Michela,Marucci, Gabriella,Marchenkova, Anna,Thomas, Ajiroghene,Nistri, Andrea,Cristalli, Gloria,Volpini, Rosaria
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supporting information
p. 41 - 50
(2013/10/01)
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- Access to "friedel-Crafts-Restricted" tert -alkyl aromatics by activation/methylation of tertiary benzylic alcohols
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Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
- Hartsel, Joshua A.,Craft, Derek T.,Chen, Qiao-Hong,Ma, Ming,Carlier, Paul R.
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experimental part
p. 3127 - 3133
(2012/05/20)
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- HELIX 12 DIRECTED STEROIDAL PHARMACEUTICAL PRODUCTS
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Compounds having the structure or their salts: are used to treat or reduce le likelihood of acquiring androgen-dependent diseases, such as prostate cancer, benign prostatic hyperplasia, polycystic ovarian syndrome, acne, hirsutism, seborrhea, androgenic alopecia and male baldness. They can be formulated together with pharmaceutically acceptable diluent or carrier or otherwise made into any pharmaceutical dosage form. Some of these compounds having tissue-specific antiandrogenic activity and tissue-specific androgenic activity can be used to treat or reduce the risk of developing diseases related to loss of androgenic stimulation. Combinations with other active pharmaceutical agents are also disclosed.
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Page/Page column 163
(2010/02/12)
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- Indium(III) bromide-catalyzed chemioselective dimerization of vinylarenes
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Indium(III) bromide catalyzes the dimerization of α-substituted vinylarenes. Chemioselectivity towards open chain or cyclic dimers depends on the nature of the substituent at the aryl group of the vinylarene.
- Peppe, Clovis,Lang, Ernesto Schulz,De Andrade, Fabiano Molinos,De Castro, Liérson Borges
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p. 1723 - 1726
(2007/10/03)
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- 1,2-DISUBSTITUTED CYCLOPROPANES
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Compounds of Formula I wherein the substituents are as described in the specification or pharmaceutically acceptable salts or stereochemically isomeric forms thereof, useful for treating diseases related to calcium imbalance and metabolism.
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- AROMATIC AMINE DERIVATIVES, PROCESS FOR THE PREPARATION THEREOF AND AGENTS CONTAINING THE SAME
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Compounds of a formula: wherein Ring A represents an optionally-substituted aromatic ring; Ring B represents an optionally-substituted cyclic hydrocarbon group; Z represents an optionally-substituted cyclic group; R1 represents a hydrogen atom, an optionally-substituted hydrocarbon group, an optionally-substituted heterocyclic group, or an acyl group; R2 represents an optionally-substituted amino group; D represents a chemical bond or a divalent group; E represents -CO-, -CON(Ra)-, COO-, -N(Ra)CON(Rb)-, -N(Ra)COO-, -N(Ra)SO2-, -N(Ra)-, -O-, -S-,-SO- or -SO2- (in which Ra and Rb each independently represent a hydrogen atom or an optionally-substituted hydrocarbon group); G represents a chemical bond or a divalent group; L represents (1) a chemical bond or (2) a divalent hydrocarbon group optionally having from 1 to 5 substituents selected from;(i) a C1-6 alkyl group,(ii) a halogeno-C1-6 alkyl group,(iii) a phenyl group,(iv) a benzyl group,(v) an optionally-substituted amino group,(vi) an optionally-substituted hydroxy group, and(vii) a carbamoyl or thiocarbamoyl group optionally substituted by: a C1-6 alkyl group, an optionally-substituted phenyl group, or an optionally-substituted heterocyclic group, and optionally interrupted by -O- or -S-; X represents an oxygen atom, an optionally-oxidized sulfur atom, an optionally-substituted nitrogen atom, or an optionally-substituted divalent hydrocarbon group; Y represents two hydrogen atoms, an oxygen atom or a sulfur atom; .... means that R2 may be bonded to the atom on Ring B to form a ring, or their salts, and a method for producing them.
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- A comparison of substituent effects on the stability of α,α-dimethylbenzyl carbocations in aqueous solution and in the gas phase: How significant is nucleophilic solvation?
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Rate and equilibrium constants for conversion of ring-substituted cumyl alcohols in acidic solutions of 50:50 (v/v) trifluoroethanol/water (I = 0.50, NaClO4) to an equilibrium mixture of the corresponding cumyl alcohol, cumyl trifluoroethyl ether, and α-methylstyrene and the fractional yields of cumyl trifluoroethyl ether obtained from partitioning of the cumyl carbocation intermediates of these reactions between capture by water and by trifluoroethanol have been determined. These data and estimates of absolute rate constants for the reaction of ring-substituted cumyl carbocations with water in 50:50 (v/v) trifluoroethanol/water30 have been used to calculate equilibrium constants KR and Kp respectively for conversion of ring-substituted cumyl carbocations to the corresponding cumyl alcohols and α-methylstyrenes and the changes in Gibbs free energy (△Gx)sol for deprotonation of ring-substituted cumyl carbocations by α-methylstyrene. A plot of (△Gx)sol against (△Gx)gas for the corresponding reactions in the gas phase is linear with a slope of 0.70, in contrast to the previously reported unitary slopes of correlations of substituent effects on carbocation stability in solution and in the gas phase. We conclude that there is a modest increase in the stabilization of ring-substituted cumyl carbocations by solvation as their stability is decreased, but that this is much smaller than the change in stabilization by solvation with the changing stability of pyridinium and anilinium ions. The possible relevance of these data to the stabilization of carbocations by nucleophilic solvation is discussed.
- Richard, John P.,Jagannadham, Vandannapu,Amyes, Tina L.,Mishima, Masaaki,Tsuno, Yuho
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p. 6706 - 6712
(2007/10/02)
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- Ring-substituted 1,1,2,2-tetraalkylated 1,2-bis(hydroxyphenyl)ethanes. 4. Synthesis, estrogen receptor binding affinity, and evaluation of antiestrogenic and mammary tumor inhibiting activity of symmetrically disubstituted 1,1,2,2-tetramethyl-1,2-bis(hydroxyphenyl)ethanes
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The syntheses of symmetrically 2,2'-disubstituted derivatives of 1,1,2,2-tetramethyl-1,2bis(4-hydroxyphenyl)ethane (1) are and of 5,5'-, and 6,6'-disubstituted derivatives of 1,1,2,2-tetramethyl-1,2-bis(3-hydroxyphenyl)ethane (6) are described (1 and 6 are strong antiestrogens with mammary tumor inhibiting activity exhibiting only slight estrogenic properties): (2,2'-substituents) F (2), Cl (3), OCH3 (4), CH3 (5); (5,5'-substituents) Cl (7); (6,6'-substituents) F (8), Cl (9), OCH3 (10), CH3 (11). The synthesis of 1-11 was accomplished by reductive coupling of the corresponding 2-phenyl-2-propanols with TiCl3 and LiAlH4. The binding affinity of the compounds to the calf uterine estrogen receptor was measured relative to that of [3H]estradiol by a competitive binding assay. With the exception of 7 and 10 all other compounds showed relative binding affinity (RBA) values between 0.5 and 6.4% that of estradiol, 2 (RBA value 6.4), and 8 and 9 (4.0 and 3.5), exceeding those of the corresponding unsubstituted 1 and 6 (3.6 and 3.0). Compounds exhibiting RBA values of >2.5% were evaluated in the mouse uterine weight test. The substituted derivatives showed an increase in uterotrophic and a decrease in antiuterotrophic activity compared to 1 and 6. Compound 2 showed a strong, dose-dependent inhibition on the DMBA-induced hormone-dependent mammary tumor of the SD-rat, exceeding that of the parent compound 1. At a dose of 5 mg/kg per day, 2 reduced total tumor area by 47% and caused a complete remission in 74% of the tumors.
- Hartmann,Schwarz,Heindl,Schonenberger
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p. 1295 - 1301
(2007/10/02)
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- Antiestrogens. Synthesis and Evaluation of Mammary Tumor Inhibiting Activity of 1,1,2,2-Tetraalkyl-1,2-diphenylethanes
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Among the newly synthesized 1,1,2,2-tetraalkyl-1,2-diphenylethanes, 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane (23) and 1,1,2,2-tetramethyl-1,2-bis(3'-hydroxyphenyl)ethane (26) were the most active compounds regarding estradiol receptor affinity, exhibiting Ka values of 0.73*108 and 0.67*108 M-1, respectively.In vivo, 23 and 26 showed only very small uterotrophic activity in the mouse.They strongly inhibited (73percent) the estrone-stimulated mouse uterine growth.Tested on the 9,10-dimethyl-1,2-benzanthracene induced hormone-dependent mammary adenocarcinoma of the Sprague-Dawley rat, compounds 23 and 26 exhibited a dose-dependent inhibition of the tumor growth, having a strong effect at a dose of 20 (mg/kg)/day (compound 23).
- Hartmann, Rolf W.,Kranzfelder, Gerhard,Angerer, Erwin, v.,Schoenenberger, Helmut
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p. 841 - 848
(2007/10/02)
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