- Target directed enediyne prodrugs: hER and AhR degradation by a synthetic oxo-enediyne
-
An efficient route to oxo-enediynes is presented. A simple oxo-enediyne has been synthesized, which cyclizes to give an isochroman. The agent shows cytotoxicity for ER rich breast cancer cells and a model for its mode of action is proposed.
- Jones, Graham B.,Kilgore, Michael W.,Pollenz, Richard S.,Li, Aiwen,Mathews, Jude E.,Wright, Justin M.,Huber, Robert S.,Tate, Patricia L.,Price, Thomas L.,Sticca, Robert P.
-
-
Read Online
- Iron-catalyzed direct C(sp3)-H amination reactions of isochroman derivatives with primary arylamines under mild conditions
-
A direct C(sp3)-H amination reaction of isochroman derivatives with arylamines was developed in the presence of iron(II) salt. A variety of isochroman derivatives and primary amines were selectively transformed into the corresponding oxidative coupling products in good to excellent yield under mild conditions. Georg Thieme Verlag Stuttgart, New York.
- Chen, Di,Pan, Fuyou,Gao, Jianrong,Yang, Jianguo
-
-
Read Online
- Iridium-Catalyzed Enantioselective Hydrogenation of Oxocarbenium Ions: A Case of Ionic Hydrogenation
-
Ionic hydrogenation has not been extensively explored, but is advantageous for challenging substrates such as unsaturated intermediates. Reported here is an iridium-catalyzed hydrogenation of oxocarbenium ions to afford chiral isochromans with high enantioselectivities. A variety of functionalities are compatible with this catalytic system. In the presence of a catalytic amount of the Br?nsted acid HCl, an α-chloroether is generated in situ and subsequentially reduced. Kinetic studies suggest first-order kinetics in the substrate and half-order kinetics in the catalyst. A positive nonlinear effect, together with the half kinetic order, revealed a dimerization of the catalyst. Possible reaction pathways based on the monomeric iridium catalyst were proposed and DFT computational studies revealed an ionic hydrogenation pathway. Chloride abstraction and the cleavage of dihydrogen occur in the same step.
- Lin, Zhenyang,Sun, Yongjie,Wang, Heng,Wen, Jialin,Yang, Tilong,Zhang, Xumu
-
supporting information
p. 6108 - 6114
(2020/03/04)
-
- Ytterbium-Catalyzed Intramolecular [3 + 2] Cycloaddition based on Furan Dearomatization to Construct Fused Triazoles
-
The 1,2,3-triazole-containing polycyclic architecture widely exists in a broad spectrum of synthetic bioactive molecules, and the development of expeditious methods to synthesize these skeletons remains a challenging task. In this work, the catalytic cyclization of biomass-derived 2-furylcarbinols with an azide to form fused triazoles is described. This approach takes advantage of a single catalyst Yb(OTf)3 and operates via a furfuryl-cation-induced intramolecular [3 + 2] cycloaddition/furan ring-opening cascade.
- Xu, Xiaoming,Zhong, Ying,Xing, Qingzhao,Gao, Ziwei,Gou, Jing,Yu, Binxun
-
supporting information
p. 5176 - 5181
(2020/07/14)
-
- Synthesis of Tetrahydroisoquinolines through an Iron-Catalyzed Cascade: Tandem Alcohol Substitution and Hydroamination
-
Rapid assembly of saturated nitrogen heterocycles - the synthetically more challenging variants of their aromatic relatives - can expedite the synthesis of biologically relevant molecules. Starting from a benzylic alcohol tethered to an unactivated alkene, an iron-catalyzed tandem alcohol substitution and hydroamination provides access to tetrahydroisoquinolines in a single synthetic step. Using a mild iron-based catalyst, the combination of these operations forms two carbon-nitrogen bonds and provides a unique annulation strategy to access this valuable core.
- Marcyk, Paul T.,Cook, Silas P.
-
p. 6741 - 6744
(2019/09/07)
-
- Enantioselective synthesis of tetrahydroisoquinoline derivatives via chiral-at-metal rhodium complex catalyzed [3+2] cycloaddition
-
An asymmetric [3+2] cycloaddition of C,N-cyclic azomethine imines with α,β-unsaturated 2-acyl imidazoles catalyzed by a chiral-at-metal rhodium complex has been developed. The corresponding C-1-substituted tetrahydroisoquinoline derivatives were obtained in high yields (>90%) with excellent stereoselectivities (up to 99% ee and >20?:?1 dr). The reaction can be conducted on a gram-scale using a low catalyst loading (0.5 mol%) with high yield and selectivity.
- Qurban, Saira,Du, Yu,Gong, Jun,Lin, Shao-Xia,Kang, Qiang
-
supporting information
p. 249 - 252
(2019/01/04)
-
- A rhodium-catalysed three-component reaction to access C1-substituted tetrahydroisoquinolines
-
A rhodium-catalyzed three-component reaction of diazo compounds, anilines and C,N-cyclic azomethine imines via trapping of transient ammonium ylides was developed. This reaction provided a simple and convenient approach for the synthesis of pharmaceutically intriguing tetrahydroisoquinoline derivatives in moderate to good yields (36-85%) with good diastereoselectivities (up to 95 : 5 dr) under mild reaction conditions.
- Zhang, Dan,Liu, Junwen,Kang, Zhenghui,Qiu, Huang,Hu, Wenhao
-
p. 9844 - 9848
(2019/12/05)
-
- Cyclic ether synthesis from diols using trimethyl phosphate
-
Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5-7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their stereochemistries.
- Asai, Shota,Kato, Maho,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
-
p. 4787 - 4790
(2017/07/06)
-
- Expanding the Strained Alkyne Toolbox: Generation and Utility of Oxygen-Containing Strained Alkynes
-
We report synthetic methodology that permits access to two oxacyclic strained intermediates, the 4,5-benzofuranyne and the 3,4-oxacyclohexyne. In situ trapping of these intermediates affords an array of heterocyclic scaffolds by the formation of one or more new C-C or C-heteroatom bonds. Experimentally determined regioselectivities were consistent with predictions made using the distortion/interaction model and were also found to be greater compared to selectivities seen in the case of trapping experiments of the corresponding N-containing intermediates. These studies demonstrate the synthetic versatility of oxacyclic arynes and alkynes for the synthesis of functionalized heterocycles, while further expanding the scope of the distortion/interaction model. Moreover, these efforts underscore the value of harnessing strained heterocyclic intermediates as a unique approach to building polycyclic heteroatom-containing frameworks.
- Shah, Tejas K.,Medina, Jose M.,Garg, Neil K.
-
supporting information
p. 4948 - 4954
(2016/05/10)
-
- Phosphane-Catalyzed [3+3] Annulation of C,N-Cyclic Azomethine Imines with Ynones: A Practical Method for Tricyclic Dinitrogen-Fused Heterocycles
-
A phosphane-catalyzed [3+3] annulation of azomethine imines with ynones has been developed. Under mild reaction conditions, the reaction proceeds smoothly to afford tricyclic dinitrogen-fused heterocyclic compounds in moderate to excellent yields with moderate to excellent stereoselectivies. Using a chiral phosphine as the catalyst, the reaction could work to give the cycloadduct in moderate yield with moderate enantioselectivity. (Figure presented.) .
- Li, Zhen,Yu, Hao,Liu, Yang,Zhou, Leijie,Sun, Zhanhu,Guo, Hongchao
-
supporting information
p. 1880 - 1885
(2016/07/06)
-
- Scaffold Diversity through a Branching Double-Annulation Cascade Strategy: Iminium-Induced One-Pot Synthesis of Diverse Fused Tetrahydroisoquinoline Scaffolds
-
A branching double-annulation cascade (BDAC) strategy for diverse and complex fused THIQ scaffolds via a highly reactive iminium-induced one-pot double-cyclization sequence involving Pictect-Spengler-type cyclization has been developed for the first time. The salient features of this protocol are that it allows direct and rapid access to unprecedented diverse fused THIQ skeletons, is metal/catalyst free, has a cleaner reaction profile, provides good to excellent yields, and is a convenient approach. This catalyst-free domino process facilitates the double annulation with a variety of scaffold building agents via two C-N and one C-X (X = C, N, O) bond formation in a single step under uniform reaction conditions. Furthermore, we reveal an unusual dual BDAC sequence leading to N-N-linked isoquinoline dimer.
- Sharada, Duddu S.,Shinde, Anand H.,Patel, Srilaxmi M.,Vidyacharan, Shinde
-
p. 6463 - 6471
(2016/08/16)
-
- Synthesis of 5,6-Dihydropyrazolo[5,1-a]isoquinoline and Ethyl (Z)-3-Acetoxy-3-tosylpent-4-enoate through Tertiary-Amine-Catalyzed [3+2] Annulation
-
The 1,4-diazabicyclo[2.2.2]octane (DABCO) catalyzed divergent [3+2] annulation of C,N-cyclic azomethine imines with δ-acetoxyallenoates was developed; 5,6-dihydropyrazolo[5,1-a]isoquinolines and ethyl (Z)-3-acetoxy-3-tosylpent-4-enoates were afforded in moderate to good yields in a one-pot manner under mild conditions. This annulation reaction provides a highly efficient method to construct dinitrogen-fused heterocycles and ethyl (Z)-3-acetoxy-3-tosylpent-4-enoates at the same time.
- Lei, Yu,Xing, Jiao-Jiao,Xu, Qin,Shi, Min
-
supporting information
p. 3486 - 3490
(2016/07/28)
-
- A metal-free cyclic iminium induced one-pot double annulation cascade: Access to dihydroisoquinolinium (DHIQ) salts
-
A reactive cyclic iminium induced one-pot Groebke-Blackburn-Bienayme (GBB) double annulation cascade (DAC) for the synthesis of skeletally diverse DHIQ salts has been described. The key features of this protocol are transition-metal and solvent-free, mild reaction conditions, robust method, one-step construction of two privileged heterocyclic rings, clean reaction profile and operational simplicity.
- Sagar,Nagarjuna Babu, Venkata,Shinde, Anand H.,Sharada, Duddu S.
-
supporting information
p. 10366 - 10370
(2016/11/18)
-
- Improved preparation method for ropinirole hydrochloride
-
The invention discloses an improved preparation method for ropinirole hydrochloride. The ropinirole hydrochloride is a compound shown in the formula I and is prepared through a series of reactions with 2-phenylethanol as a starting raw material. Compared with the prior art, according to the method, raw materials are cheap and easy to get, reaction conditions are mild, technological operation is easy, control is easy, the product is high in total yield and purity, and the method is suitable for industrial production.
- -
-
Paragraph 0030; 0031; 0032; 0033
(2016/10/09)
-
- Tetrahydroisoquinoline compounds as preparing animal miticiding the application of the medicament
-
The invention discloses application of a tetrahydroisoquinoline compound for preparing a drug killing animal mites. The compound has the molecular structure feature shown in the specification, wherein R is ortho-, meta- or para-alkyl, alkoxy, halogen, hydroxyl, nitro, trifluoromethyl, cyano group and the like. The compound has good activity in killing multiple animal mites like psoroptes communis cuniculi, which is superior to that of the clinical mite killing drug ivermectin, and has chemical stability and good compatibility with physiological environment.
- -
-
Paragraph 0023
(2016/10/07)
-
- Pd/phenanthroline-catalyzed arylative cyclization of o-(1-alkynyl)thioanisoles: Synthesis of 3-arylated benzo[b]thiophenes
-
The arylative cyclization of o-(1-alkynyl)thioanisoles with aryl iodides in the presence of catalytic amounts of [Pd(phen)2][PF6]2resulted in the efficient formation of 3-arylated benzo[b]thiophenes, and a range of aryl iodides with electron-donating or -withdrawing groups could be used. While this reaction proceeded in the presence of aromatic and aliphatic groups on the terminal alkynyl carbon atom, silyl and alkoxycarbonyl groups hampered the reaction. Furthermore, this method could be extended to the synthesis of 3-arylated indoles from N,N-dimethyl-o-(1-alkynyl)aniline. All these reactions proceeded smoothly via cleavage of the carbon-heteroatom bond. In addition to the desired cyclization products, the use of a o-(hydroxypropyl)phenylmethyl substituent on the sulfur atom afforded isochroman, which should be formed by the intramolecular attack of a hydroxy group onto the benzylic carbon atom.
- Yamauchi, Takayuki,Shibahara, Fumitoshi,Murai, Toshiaki
-
p. 2945 - 2948
(2016/07/06)
-
- Lewis acid promoted ruthenium(II)-catalyzed etherifications by selective hydrogenation of carboxylic acids/esters
-
Ethers are of fundamental importance in organic chemistry and they are an integral part of valuable flavors, fragrances, and numerous bioactive compounds. In general, the reduction of esters constitutes the most straightforward preparation of ethers. Unfortunately, this transformation requires large amounts of metal hydrides. Presented herein is a bifunctional catalyst system, consisting of Ru/phosphine complex and aluminum triflate, which allows selective synthesis of ethers by hydrogenation of esters or carboxylic acids. Different lactones were reduced in good yields to the desired products. Even challenging aromatic and aliphatic esters were reduced to the desired products. Notably, the in situ formed catalyst can be reused several times without any significant loss of activity. An assist from Al: A bifunctional catalyst system consisting of a Ru/phosphine complex and aluminum triflate allows selective hydrogenation of esters to ethers. A variety of lactones were reduced to the desired products in good yields. The catalyst further provides a general method for the reduction of linear esters and reductive etherification of carboxylic acids with alcohols.
- Li, Yuehui,Topf, Christoph,Cui, Xinjiang,Junge, Kathrin,Beller, Matthias
-
p. 5196 - 5200
(2015/04/27)
-
- Visible light mediated efficient oxidative benzylic sp3 C-H to ketone derivatives obtained under mild conditions using O2
-
A photooxygenation of benzylic sp3 C-H reaction has been demonstrated using O2 mediated by visible light. This protocol provides a simple and mild route to obtain ketones from benzylic sp3 C-H bonds. Various benzylic sp3 C-H bonds can be transformed into the desired ketone derivatives in moderate to good yields. The 18O2 labelling experiments demonstrated that the oxygen introduced into ketone originated from dioxygen. A plausible mechanism has been proposed accordingly.
- Yi, Hong,Bian, Changliang,Hu, Xia,Niu, Linbin,Lei, Aiwen
-
supporting information
p. 14046 - 14049
(2015/09/15)
-
- A facile one-pot protocol for the synthesis of tetrazolyl-tetrahydroisoquinolines via novel domino intramolecular cyclization/Ugi-azide sequence
-
A facile one-pot, four-component domino reaction between 2-(2-bromoethyl)benzaldehyde, isocyanide, amine, and azide for the synthesis of tetrazolyl-tetrahydroisoquinoline derivatives has been developed. The reaction sequence involves intramolecular replacement of halide by iminium nitrogen followed by Ugi-azide reaction. The reaction is catalyst/additive free and takes place under ambient conditions with short reaction times to furnish products in good to excellent yields.
- Shinde, Anand H.,Archith,Malipatel, Srilaxmi,Sharada, Duddu S.
-
supporting information
p. 6821 - 6826
(2015/01/09)
-
- A Phosphine-Catalyzed Novel Asymmetric [3+2] Cycloaddition of C,N-Cyclic Azomethine Imines with δ-Substituted Allenoates
-
Catalytic asymmetric [3+2] cycloadditions of C,N-cyclic azomethine imines with δ-substituted allenoates have been developed in the presence of (S)-Me-f-KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo- and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ-substituted allenoates have been applied as a δ,γ-C-C bond participated C 2 synthon in asymmetric synthesis. Another round: Catalytic asymmetric [3+2] cycloaddition of C,N-cyclic azomethine imines with δ-substituted allenoates have been developed in the presence of (S)-Me-f-KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo- and good enantioselectivities under mild conditions. This is the first example applying δ-substituted allenoates as C 2 synthons in asymmetric δ,γ-C-C bond formation.
- Wang, De,Lei, Yu,Wei, Yin,Shi, Min
-
supporting information
p. 15325 - 15329
(2016/02/18)
-
- Selective catalytic synthesis of unsymmetrical ethers from the dehydrative etherification of two different alcohols
-
The cationic ruthenium-hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4- catalyzes selective etherification of two different alcohols to form unsymmetrically substituted ethers. The catalytic method exhibits a broad substrate scope while tolerating a range of heteroatom functional groups in forming unsymmetrical ethers, and it is successfully used to directly synthesize a number of highly functionalized chiral nonracemic ethers.
- Kim, Junghwa,Lee, Dong-Hwan,Kalutharage, Nishantha,Yi, Chae S.
-
p. 3881 - 3885
(2015/01/16)
-
- CuBr2 catalyzed bromination/oxidation of isochromans to benzaldehyde derivatives
-
A series of isochromans were oxidized and brominated by using 1.2 equiv of CuBr2 in CH3CN at reflux to give the corresponding bromo benzaldehydes in moderate yields. A plausible mechanism for this transformation has been suggested.
- Zhou, Mei-Yan,Kong, Shan-Shan,Zhang, Ling-Qiong,Zhao, Ming,Duan, Jin-Ao,Ou-Yang, Zhen,Wang, Min
-
supporting information
p. 3962 - 3964
(2013/07/25)
-
- In situ generation of nucleophilic allenes by the gold-catalyzed rearrangement of propargylic esters for the highly diastereoselective formation of intermolecular C(sp3)-C(sp2) bonds
-
New perspectives, in particular for the synthesis of isochromane derivatives (see scheme), are provided by the title reaction. Excellent diastereoselectivites are achieved in this reaction which proceeds through a gold-catalyzed 1,3-acyloxy migration. In some cases exclusively the Z isomer is detected. Copyright
- Yu, Yang,Yang, Weibo,Rominger, Frank,Hashmi, A. Stephen K.
-
supporting information
p. 7586 - 7589
(2013/07/26)
-
- Formation of C-O bond via cross-dehydrogenative coupling between isochroman and oxime under metal-free oxidation conditions
-
DDQ-mediated C-O bond formation through cross-dehydrogenative coupling (CDC) reaction without any metal catalyst under mild conditions was developed. Series of isochromans and oximes could be employed as substrates, and the products were obtained in good yields. Georg Thieme Verlag Stuttgart New York.
- He, Hua-Feng,Wang, Kai,Xing, Bo,Sheng, Guorong,Ma, Tingxuan,Bao, Weiliang
-
supporting information
p. 211 - 214
(2013/03/13)
-
- A facile synthesis of 5,6-dihydro-4H-pyrrolo[3,4-d]thiazole and other pyrrolidine-fused aromatic ring systems via one-step cyclization from diols
-
A facile synthetic method of 5,6-dihydro-4H-pyrrolo[3,4-d]thiazole, which is a subunit of a potent factor Xa (fXa) inhibitor was developed. This new approach employs one-step cyclization from a diol and can be applied to the syntheses of other pyrrolidine-fused aromatic ring sytems.
- Yoshikawa, Kenji,Nagata, Tsutomu,Yoshino, Toshiharu,Nakamoto, Yumi,Haginoya, Noriyasu,Muto, Ryo,Mochizuki, Akiyoshi,Kanno, Hideyuki,Ohta, Toshiharu
-
experimental part
p. 1711 - 1720
(2012/09/07)
-
- Synthesis of 3-substituted tetrahydrofuran and 4-substituted tetrahydropyran derivatives by cyclization of dicarboxylic acids with InBr 3/TMDS
-
An efficient reduction followed by cyclization of diacid compounds with the InBr3/TMDS system is reported. This system allows the formation of five- and six-membered ring ethers substituted in the 3- or 4-position. Copyright
- Pehlivan, Leyla,Metay, Estelle,Delbrayelle, Dominique,Mignani, Gerard,Lemaire, Marc
-
supporting information; experimental part
p. 4689 - 4693
(2012/09/22)
-
- Copper-catalyzed enantioselective additions to oxocarbenium ions: Alkynylation of isochroman acetals
-
We have developed an enantioselective, copper(I)-catalyzed addition of terminal alkynes to racemic isochroman acetals. This method is one of the first transition-metal-catalyzed approaches to enantioselective additions to prochiral oxocarbenium ions. In this reaction, TMSOTf is used to form the oxocarbenium ion in situ under conditions compatible with simultaneous formation of the chiral copper acetylide. By using a bis(oxazoline) ligand, good yields and enantioselectivities are observed for a variety of enantioenriched 1-alkynyl isochromans.
- Maity, Prantik,Srinivas, Harathi D.,Watson, Mary P.
-
supporting information; experimental part
p. 17142 - 17145
(2011/12/13)
-
- FLUOROBORON COMPOUND HAVING AROMATIC RING OR SALT THEREOF, AND PROCESS FOR PRODUCTION OF COMPOUND HAVING CYCLIC ETHER-FUSED AROMATIC RING BY USING THE SAME
-
Provided is a fluoroboron compound which is highly safe and stable and is capable of forming a cyclic ether-fused ring by the intramolecular alkoxymethylation reaction, or a salt thereof. The compound can be synthesized by the intramolecular alkoxymethylation reaction of a fluoroboron compound represented by the formula (I) or a salt thereof in the presence of a metal catalyst. (wherein the moiety represented by the formula represents an aromatic ring; L represents a substituent such as a halogen atom; R represents a substituted or unsubstituted alkylene group having 1 or 2 carbon atoms; and M represents an alkali metal cation or the like, with the proviso that L and -R-OCH2BF3M are respectively located on contiguous carbon atoms on the aromatic ring, or in the case of a fused aromatic ring, on two carbon atoms adjacent to one carbon at the fused position).
- -
-
Page/Page column 14
(2009/06/27)
-
- Direct reduction of esters to ethers with an indium(III) bromide/triethylsilane catalytic system
-
An indium(III) bromide-triethylsilane reagent system promotes direct reduction of esters to produce the corresponding unsymmetrical ethers. This simple catalytic system accommodated other carbonyl compounds, such as a tertiary amide and a carboxylic acid. Georg Thieme Verlag Stuttgart.
- Sakai, Norio,Moriya, Toshimitsu,Fujii, Kohji,Konakahara, Takeo
-
experimental part
p. 3533 - 3536
(2009/05/07)
-
- Oxidative C-C bond cleavage of primary alcohols and vicinal diols catalyzed by H5PV2Mo10O40 by an electron transfer and oxygen transfer reaction mechanism
-
Primary alcohols such as 1-butanol were oxidized by the H5PV2Mo10O40 polyoxometalate in an atypical manner. Instead of C-H bond activation leading to the formation of butanal and butanoic acid, C-C bond cleavage took place leading to the formation of propanal and formaldehyde as initial products. The latter reacted with the excess 1-butanol present to yield butylformate and butylpropanate in additional oxidative transformations. Kinetic studies including measurement of kinetic isotope effects, labeling studies with 18O labeled H5PV2Mo10O40, and observation of a prerate determining step intermediate by 13C NMR leads to the formulation of a reaction mechanism based on electron transfer from the substrate to the polyoxometalate and oxygen transfer from the reduced polyoxometalate to the organic substrate. It was also shown that vicinal diols such as 1,2-ethanediol apparently react by a similar reaction mechanism. Copyright
- Khenkin, Alexander M.,Neumann, Ronny
-
supporting information; scheme or table
p. 14474 - 14476
(2009/02/08)
-
- An efficient one-pot synthesis of unsymmetrical ethers: A directly reductive deoxygenation of esters using an InBr3/Et3SiH catalytic system
-
(Chemical Equation Presented) This study describes a novel one-pot procedure for a directly reductive conversion of the carbonyl function of esters to the corresponding ethers by Et3SiH in the presence of a catalytic amount of InBr3.
- Sakai, Norio,Moriya, Toshimitsu,Konakahara, Takeo
-
p. 5920 - 5922
(2008/02/09)
-
- Mechanistic studies on the cyclizatlon of (Z)-1,2,4-heptatrien-6-yne in methanol: A possible nonadiabatic thermal reaction
-
Myers et al. pyrolyzed (Z)-1,2,4-heptatrien-6-yne (1) in methanol at 100°C and observed benzylmethyl ether (2) as a major product and 2-phenylethanol (3) as a minor product. If a biradical intermediate, such as the open-shell singlet state of α,3-didehydrotoluene (4), was the only intermediate generated by the cyclization, then reaction with methanol might be expected to afford 2-phenylethanol as the principal product. The question that has been of interest since its first discovery is the origin of the principal product of the title reaction, benzylmethyl ether. This report considers three mechanisms for formation of the benzylmethyl ether: direct methanol participation in the cyclization of the reactant, partial ether formation from the biradical 4, or involvement of the closed-shell zwitterionic state of α,3-didehydrotoluene (5). A fourth mechanism, involving a cyclic allene intermediate, has been ruled out by earlier studies. In the present work, the first two mechanisms are ruled out by experiment and/or calculation. The remaining one, involving the zwitterion, is shown to be consistent with experimental and computational data only if a component of the reaction follows a nonadiabatic course.
- Cremeens, Matthew E.,Hughes, Thomas S.,Carpenter, Barry K.
-
p. 6652 - 6661
(2007/10/03)
-
- PROCESS FOR PURIFICATION OF ROPINIROLE
-
The invention discloses an improved process for the purification of ropinirole hydrochloride by dissolving or suspending crude ropinirole base or its pharmaceutically acceptable salt in a suitable solvent, reacting with a nitrogenous base to form an imine derivative, optionally treating the reaction mixture with a base to adjust the pH, and isolating purified ropinirole hydrochloride. The invention also provides for a pharmaceutical composition comprising pure ropinirole hydrochloride as active ingredient.
- -
-
Page/Page column 19
(2010/02/13)
-
- CONDENSED 2,3-BENZODIAZEPINE DERIVATIVES AND THIER USE AS AMPA-RECEPTOR INHIBITORS
-
Compounds of formula I are described, their production and use in pharmaceutical agents.
- -
-
-
- Perfluorosulfonylmethide compounds; use thereof for carbon-carbon bond formation
-
Free perfluorosulfonylmethide compounds and metal salts thereof show strong catalytic activity in carbon-carbon bond formation reactions, in amounts as low as 0.1 mole %. Fluorous media may be used, especially biphasic fluorous media enabling ready recycling of the catalyst. The formula thereof is: M[C(SO2R1)3?(m+q)(SO2R2)m(SO2R3)q]xwhere M is H, Sc, Y, La, Ce, Pr, Nd, Sm Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Zr, Hf, Th, Nb, Ta, U, Bi, Al, Ga, In or Tl, x is the common oxidation state of a said metal M, R1, R2and R3are perfluorinated or polyfluoronated hydrocarbon, ether or amine moieties or mixtures thereof and m+q=0, 1, 2 or 3 (m and q being zero or integers).
- -
-
Page column 11-12
(2010/02/06)
-
- Oxa-enediynes: Probing the electronic and stereoelectronic contributions to the bergman cycloaromatization
-
Efficient routes to three classes of 10-membered oxa-enediynes are presented. The electronic and stereoelectronic contributions to half-lives are supported by density functional theory calculations. One member of this class cyclizes to give an isochroman which binds to and degrades the aryl hydrocarbon receptor (AhR).
- Jones, Graham B.,Wright, Justin M.,Hynd, George,Wyatt, Justin K.,Warner, Philip M.,Huber, Robert S.,Li, Aiwen,Kilgore, Michael W.,Sticca, Robert P.,Pollenz, Richard S.
-
p. 5727 - 5732
(2007/10/03)
-
- Isoquinolones
-
Benzo[de]isoquinoline-1,3-dione of Formula or a pharmaceutically acceptable salt thereof wherein R is hydrogen or a protecting group typically used in the art for protecting alcohols and R1-R5are each independently chosen from H, Cl, Br, F, straight or branched alkyl C1-C8alkyl, C3-C8cycloalkyl, heterocycle or bridged heterocycle of 4-9 atoms containing 1-3 heteroatoms, —(CR′2)nOR6, —(CR′2)nN(R6)2, —(CR′2)nNR6COR7, —(CR′2)nNR6SO2OR7, —(CR′2)nNR6SO2N(R6)2, —(CR′2)nOSO2N(R6)2, —(CR′2)nCN, —(CR′2)n(NOR6)R7, NO2, CF3, —(CR′2)nSOmR7, —(CR′2)nSOmR7, —(CR′2)nCO2R6, —(CR′2)nCON(R6)2, Ph, and any two of R1-R5may form a substituted or unsubstituted ring of 5-7 total atoms having 0-2 heteroatoms are claimed which are selective inhibitors of bacterial DNA gyrase and DNA topoisomerase useful in antibacterial agents. Methods for their preparation and formulation as well as novel intermediates useful in the preparation of the final products are also claimed.
- -
-
-
- Process for preparing isochroman compounds
-
High-purity isochroman compounds can be obtained in high yields according to a simple and economical process for preparing isochroman compounds, comprising the step of adding an aquesous solution of formaldehyde having a concentration of 40 to 70 wt. % to a complex of an arylalkanol represented by the following general formula (II) with a Friedel-Crafts catalyst to cyclize the arylalkanol: STR1 wherein R1 and R2 each stands for a hydrogen atom, a lower alkyl group or a lower alkoxyl group, or alternatively R1 and R2 are respectively bonded to adjacent carbon atoms with mutual bonding of R1 and R2 together with the carbon atoms respectively bonded to R1 and R2 to form a benzene ring, a naphthalene ring, or a C5 or C6 cycloalkane or cycloalkene which may have 1 to 6 lower alkyl groups; and R3 stands for a hydrogen atom or a lower alkyl group.
- -
-
-
- Antineoplastic heteronapthoquinones
-
This invention relates to a naphthoquinone derivatives, to processes and to intermediates for preparing these derivatives, to pharmaceutical composition and to the use of these derivatives as antitumor agents in mammals.
- -
-
-
- Processes antineoplastic heteronaphthoquinones
-
This invention relates to a naphthoquinone derivatives, to processes and to intermediates for preparing these derivatives, to pharmaceutical composition and to the use of these derivatives as antitumor agents in mammals.
- -
-
-
- Heterocyclic anthracycline analogs
-
Novel pyrano heterocyclic anthracycline derivatives are described, which are useful in the treatment of cancer and tumors, such as breast cancer, leukemia, lung cancer, colon cancer, ovarian cancer, renal cancer, and melanoma. As well, these compounds may be used ex vivo for the treatment of cancerous bone marrow before retransplanting said marrow in a patient. Pharmaceutical compositions and methods of preparing the compounds are also described.
- -
-
-
- A new synthesis of isochromans and phtalans
-
A short and efficient synthesis of isochromans and phtalans has been devised. This synthesis involves the intramolecular Friedel-Crafts cyclialkylation of oxonium species generated by reaction of MEM ethers with Lewis acids.
- Ahmar,Bloch
-
p. 1417 - 1420
(2007/10/02)
-
- Carbenes and the O-H Bond: Hydroxyalkyl-Substituted Arylcarbenes
-
carbene (4), phenylcarbene (19), and carbene (30) have been generated by photolysis of tosylhydrazone or diazo precursors in protic solvents.These carbenes give cyclic ethers (7, 18, 33) competitively with insertion into O-H bonds of the solvent.For comparison, the analogous benzyl cations (9, 17, 31) have been generated by solvolysis or dediazoniation.The cations are more sensitive to structural variation than their carbenic counterparts: 9 does not undergo intramolecular nucleophilic substitution, in contrast to 17 and 31.These observations are explicable in terms of high barriers for rotation about aryl-cation bonds, as compared with low barriers for rotation about aryl-carbene bonds.Two major effects of the solvent (ROH) and of the base (RONa) on product formation may be distinguished: (i) protonation of the carbene (or of its precursors) in the more acidic media leads to predominantly cationic processes; (ii) deprotonation of the OH group under strongly basic conditions enhances the nucleophilicity of the oxygen, and also facilitates insertion into the α-C-H bonds of 30.
- Kirmse, Wolfgang,Kund, Klaus
-
p. 2325 - 2332
(2007/10/02)
-
- Intramolecular Generation of Oxonium Ylides from Functionalized Arylcarbenes
-
Arylcarbenes carrying alkoxyalkyl groups in the ortho position have been generated by flash pyrolysis and photolysis of appropriate tosylhydrazone sodium salts.In the gas phase and in a aprotic solvents, interaction of the carbenes with the lone electron pairs of oxygen competes efficiently with insertion into C-H bonds.Both five- and six-membered cyclic oxonium ylides have been generated.The ylides 23, 37, 61b, and 74 undergo 1,2 shifts of benzyl groups with ease, even if ring contraction to highly strained benzocyclobutenes is involved (23, 74).The oxonium ylides37 and 61b strongly prefer the nonconcerted Stevens rearrangement to the sigmatropic Sommelet rearrangement, in contrast to analogous ammonium ylides.Alkyl shifts occur to a very minor extent, if at all.Evidence is presented that alcohols intercept both the carbenes and the oxonium ylides.Protonation of the ylides leads to cyclic oxonium ions, which undergo nucleophilic cleavage of the C-O bonds.Acid catalyzed decomposition of the appropriate diazo compounds gives rise to six-membered, but not to five-membered, cyclic oxonium ions, thus confirming the different intramolecular reactivities of arylcarbenes and benzyl cations.The efficiency of carbene interception increases with increasing acidity of the medium, suggesting nucleophilic behavior (protonation) of the arylcarbenes.
- Kirmse, Wolfgang,Kund, Klaus
-
p. 1465 - 1473
(2007/10/02)
-
- Chemotherapeutic agents
-
A method of treating or preventing viral infections, in particular rhinovirus infections comprising the administration of an effective amount of a 2-phenyltetralin derivative or a heterocyclic analogue thereof. Pharmaceutical compositions containing these compounds, and some novel compounds are also disclosed.
- -
-
-
- SYNTHESIS OF ISOCHROMANS VIA THE TITANIUM TETRACHLORIDE ASSISTED CYCLIZATION OF ACETALS OF PHENETHYL ALCOHOLS
-
This paper reports the preparation of five 3,4-dihydro-1H-2-benzopyrans in good yields via the TiCl4 promoted cyclization of acetals derived from phenethyl alcohols.
- Mohler, Debra L.,Thompson, David W.
-
p. 2567 - 2570
(2007/10/02)
-
- Preparation of isochromane derivatives
-
A process for the preparation of an isochromane of the formula STR1 in which R 1 and R 2 are identical or different and denote hydrogen, lower alkyl or lower alkoxy, or together form a cyclopentane or cyclohexane ring which is optionally substituted by lower alkyl andR 3 denotes hydrogen or lower alkyl,comprising reacting an alcohol of the formula STR2 with formaldehyde and a carboxylic acid anhydride of the formula STR3 or with a methylene diester of the formula STR4 in which R 4 represents a lower alkyl radical, in the presence of an acid catalyst. The products are known, having a musk-like odor.
- -
-
-
- Reactivity of Isocoumarins. II. Reaction of 1-Ethoxyisochroman with nucleophilic reagents
-
The C(1)-position of 1-ethoxyisochroman (3) is very susceptible to attack by various nucleophilic reagents.Reaction of 3 with various alcohols, such as benzyl alcohols, N,N-dimethylaminoethanol and ethyl lactate, gave corresponding 1-alkoxyisochromans (5,7,8 and 9).Reaction of 3 with phenols, such as phenol and methyl p-hydroxybenzoate, gave 1-(hydroxyphenyl)isochromans (11, 12, 13 and 16).Some monoalkoxybenzenes were unreactive with 3 but 1,3-dimethoxybenzene gave corresponding 1-(dimethoxyphenyl)isochromans (14 and 15).Reaction of 3 with an emanine such as 1-morpholino-1-cyclohexene gave 2-(1-isochromanyl)-1-(4-morpholino)cyclohexene, which was hydrolyzed to give 2-(1-isochromanyl)cyclohexanone (17).Reaction of 3 with ketones, i.e., cyclohexanone and ethyl acetoacetate, gave 17 and ethyl α-(1-isochromanyl)acetoacetate (18), respectively.
- Yamato, Masatoshi,Ishikawa, Tadataka,Kobayashi, Toshio
-
p. 2967 - 2971
(2007/10/02)
-