- Iminyl Radical-Triggered Intermolecular Distal C(sp3)-H Heteroarylation via 1,5-Hydrogen-Atom Transfer (HAT) Cascade
-
An efficient iron-catalyzed intermolecular remote C(sp3)-H heteroarylation of alkyl ketones has been developed via an iminyl radical-triggered 1,5-hydrogen-atom transfer (HAT) cascade. This protocol was amenable to a wide variety of alkyl ketones and heteroaryls, thus providing a straightforward method for the late-stage functionalization of alkylketones and heteroaryls.
- Gu, Yu-Rui,Duan, Xin-Hua,Chen, Li,Ma, Zhi-Yong,Gao, Pin,Guo, Li-Na
-
supporting information
p. 917 - 920
(2019/02/14)
-
- Transition-Metal-Free Oxidative Aliphatic C-H Azidation
-
The first example of a practical and selective azidation of unactivated aliphatic C-H bonds with easily handled sulfonyl azides as azide source without the use of transition metals has been explored. This method is operationally simple, scalable, and applicable to late-stage azidation of natural products and derivatives, which make it a valuable method for the synthesis of organic azides.
- Zhang, Xiaofei,Yang, Haodong,Tang, Pingping
-
supporting information
p. 5828 - 5831
(2015/12/11)
-
- Silver-mediated oxidative aliphatic C-H trifluoromethylthiolation
-
The first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic C-H bonds employs a silver-based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional-group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural-product derivatives.
- Guo, Shuo,Zhang, Xiaofei,Tang, Pingping
-
p. 4065 - 4069
(2015/03/30)
-
- Half-open ferrocenes and ruthenocenes containing an edge-bridged open indenyl ligand
-
Potassium 1,1-dimethyl-1,2-dihydronaphthalenide, K(eboInd) (1), was synthesized in three steps from 4,4-dimethyl-1-tetralone and used for the synthesis of half-open metallocenes containing an edge-bridged open indenyl ligand (eboInd). Successive treatment of [(THF)FeI2] with Li(C 5Me5) and 1 at low temperatures afforded [(η5-C5Me5)Fe(η5-eboInd)] (2), whereas [(η5-C5Me5) Ru(η5-eboInd)] (3) was synthesized by reaction of 1 with [(C 5Me5)RuCl]4. Both compounds reacted with CO and 2,6-dimethylphenyl isocyanide (CN-o-Xy) to form [(η5-C 5Me5)M(η3-eboInd)L] (4: M = Fe, L = CO; 5: M = Ru, L = CO; 6: M = Fe, L = CN-o-Xy; 7: M = Ru, L = CN-o-Xy), in which the eboInd ligand has undergone an η5-to-η3 hapticity conversion. In contrast, the N-heterocyclic carbene 1,3,4,5- tetramethylimidazolin-2-ylidene (IMe) only reacted with the ruthenocene derivative 3 to give [(η5-C5Me5) Ru(η3-eboInd)(IMe)] (8). The molecular structures of 2-7 were determined by X-ray diffraction analysis. None of the iron-ruthenium pairs are isotypic.
- Volbeda, Jeroen,Daniliuc, Constantin G.,Jones, Peter G.,Tamm, Matthias
-
p. 5918 - 5925
(2013/11/19)
-
- Copper-catalyzed oxaziridine-mediated oxidation of C-H bonds
-
The highly regio- and chemoselective oxidation of activated C-H bonds has been observed via copper-catalyzed reactions of oxaziridines. The oxidation proceeded with a variety of substrates, primarily comprising allylic and benzylic examples, as well as one example of an otherwise unactivated tertiary C-H bond. The mechanism of the reaction is proposed to involve single-electron transfer to the oxaziridines to generate a copper-bound radical anion, followed by hydrogen atom abstraction and collapse to products, with regeneration of the catalyst by a final single-electron transfer event. The involvement of allylic radical intermediates was supported by a radical-trapping experiment with TEMPO.
- Motiwala, Hashim F.,Guelgeze, Belgin,Aube, Jeffrey
-
p. 7005 - 7022
(2012/10/08)
-
- COMPOUNDS AND METHODS OF USE
-
Selected compounds are effective for prophylaxis and treatment of diseases, such as angiogenesis mediated diseases. The invention encompasses novel compounds, analogs, prodrugs and pharmaceutically acceptable salts thereof, pharmaceutical compositions and methods for prophylaxis and treatment of diseases and other maladies or conditions involving, cancer and the like. The subject invention also relates to processes for making such compounds as well as to intermediates useful in such processes.
- -
-
Page/Page column 108
(2010/11/27)
-
- 7-aryl 1,5-dihydro-4, 1-benzoxazepin-2(3H)-one derivatives and their use as progesterone receptor modulators
-
This invention provides progesterone receptor modulators having the structure: wherein R1 to R7, X, and Q are as defined in the specification; or a pharmaceutically acceptable salt thereof.
- -
-
Page/Page column 35
(2008/06/13)
-
- Clarification of the binding mode of teleocidin and benzolactams to the Cys2 domain of protein kinase Cδ by synthesis of hydrophobically modified, teleocidin-mimicking benzolactams and computational docking simulation
-
Phorbol esters (12-O-tetradecanoylphorbol 13-acetate; TPA) and teleocidins are known to be potent tumor promoters and to activate protein kinase C (PKC) by binding competitively to the enzyme. The relationship between the chemical structures and the activities of these compounds has attracted much attention because of the marked structural dissimilarities. The benzolactam 5, with an eight-membered lactam ring and benzene ring instead of the nine-membered lactam ring and indole ring of teleocidins, reproduces the active ring conformation and biological activities of teleocidins. Herein we describe the synthesis of benzolactams with hydrophobic substituents at various positions. Structure-activity data indicate that the existence of a hydrophobic region between C-2 and C-9 and the steric factor at C-8 play critical roles in the appearance of biological activities. We also computationally simulated the docking of teleocidin and the modified benzolactam molecules to the Cys2 domain structure observed in the crystalline complex of PKCδ with phorbol 13-acetate. Teleocidin and benzolactams fitted well into the same cavity as phorbol 13-acetate. Of the three functional groups hydrogenbonding to the protein, two hydrogen-bonded with protein atoms in common with phorbol 13-acetate, but the third one hydrogen-bonded with a different protein atom from that in the case of phorbol 13-acetate. The model explains well the remarkable difference in activity between 5 and its analogue having a bulky substituent at C-8.
- Endo, Yasuyuki,Takehana, Shunji,Ohno, Michihiro,Driedger, Paul E.,Stabel, Silvia,Mizutani, Miho Y.,Tomioka, Nobuo,Itai, Akiko,Shudo, Koichi
-
p. 1476 - 1496
(2007/10/03)
-
- Structure-Activity Relationships among DNA Gyrase Inhibitors. Synthesis and Biological Evaluation of 1,2-Dihydro-4,4-dimethyl-1-oxo-2-naphthalenecarboxylic Acids as 1-Carba Bioisosteres of Oxolinic Acid
-
A series of oxolinic acid analogues was synthesized in an attempt to evaluate the role, if any, played by the N-1 atom in putative modes of action of antimicrobial DNA gyrase inhibitors.Carba analogues were prepared because these have no possibility of an internal resonance contribution of the nitrogen atom and yet could otherwise satisfy electronic requirements of putative modes of action.Successful routes were developed involving Friedel-Craft's cycloaddition of suitable aromatic compounds with 4,4-dimethylbutyrolactone,, followed by ethoxycarbonylation, oxidationwith dichlorodicyanobenzoquinone, and careful saponification.The gem-dimethyl group of these analogues prevents aromatization at the cost of nonplanarity.Only the unsubstituted parent compound, 1,2-dihydro-4,4-dimethyl-1-oxo-2-naphthalenecarboxylic acid (9e), possessed any appreciable antimicrobial activity in vitro.This may be due to a different mode of action, however, since 9e gave no measurable inhibition of DNA gyrase in vitro.Thus, the N-1 atom plays a significant role in enzymic and bacteriological inhibition that cannot be compensated for by the presence of C-6 oxygen atoms.
- Hoegberg, Thomas,Khanna, Ish,Drake, Steven D.,Mitscher, Lester A.,Shen, Linus L.
-
p. 306 - 310
(2007/10/02)
-
- ACID CATALIZED RING CLOSURE REACTINOS OF ELECTROPHILIC ALKENES
-
Treatment of α-acyl-α,β-unsaturated ketones with sulfuric acid or dimethylformamide-hydrogen chloride or p-toluenesulfonic acid gave rise to 3-acyl-2-alkyl-4,5-dihydrofurans.Similar cyclization of α-acyl-α,β-unsaturated esters initially afforded 3-alkoxycarbonyl-2-alkyl-4,5-dihydrofurans which were transformed into 2-acylbutanolides on further reaction with sulfuric acid.This acid catalized cyclization is strongly dependent upon the substitution pattern of the electrophilic alkenes, the acid used and reaction conditions.
- Verhe, Roland,Kimpe, Norbert De,Courtheyn, Dirk,Buyck, Laurent De,Schamp, Niceas
-
p. 3649 - 3660
(2007/10/02)
-