cas 21573-69-3, 1-Phenylcyclopentanecarboxaldehyde

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A first homogeneous gold(III)-catalysed epoxidation of aromatic alkenes
The first example of a homogeneous gold(III)-catalysed epoxidation of aromatic alkenes at room temperature using sodium chlorite as the stoichiometric oxidant in a homogeneous trisolvent system of 2-methoxyethanol/acetonitrile/ water (volume ratio: 1/3/1)
Li, Xiao-Qiang,Li, Chen,Song, Fan-Bo,Zhang, Chi
p. 722 - 724
(2007)
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An Efficient, Catalytic Procedure for Epoxide Rearrangement
Exceptionally bulky, oxygenophilic methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (reagent A) can be utilized as an active catalyst for the transformation of various epoxides to carbonyl compounds with high efficiency and selectivity.
Maruoka, Keiji,Nagahara, Shigeru,Ooi, Takashi,Yamamoto, Hisashi
p. 5607 - 5610
(1989)
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Kinetic Resolution of Neopentylic Secondary Alcohols by Cu-H-Catalyzed Enantioselective Silylation with Hydrosilanes
A nonenzymatic kinetic resolution of sterically congested alcohols having a quaternary carbon atom in the β-position is reported. The catalyst system CuCl/NaOtBu/(R,R)-Ph-BPE together with a 3,5-xylyl-substituted tertiary hydrosilane enable enantioselective silylation of the hydroxy group. Several alcohols are obtained with good to excellent selectivity factors, and there are no other known straightforward methods to access these motifs.
Oestreich, Martin,Papadopulu, Zaneta
supporting information
p. 438 - 441
(2021/01/13)

Preparation of isoquinazolines: Via metal-free [4 + 2] cycloaddition of ynamides with nitriles
TfOH-mediated [4 + 2] cycloaddition of ynamides with nitriles to construct 1,2-dihydroquinazolines is realized by a direct reaction in moderate to excellent yields (up to 93%) in a stereospecific manner. A rapid and efficient strategy has been employed for the syntheses of alkyl-substituted 1,2-dihydroquinazoline derivatives, and it exhibits good functional group tolerance, has a short reaction time, shows excellent diastereoselectivity, and is a simple and high-yielding reaction.
Wu, Hao,Liu, Yu,He, Ming-Xing,Wen, Hao,Cao, Wei,Chen, Ping,Tang, Yu
p. 8408 - 8416
(2019/09/30)

Nickel-Catalyzed Selective Reduction of Carboxylic Acids to Aldehydes
The direct reduction of carboxylic acids to aldehydes is a fundamental transformation in organic synthesis. The combination of an air-stable Ni precatalyst, dimethyl dicarbonate as an activator, and silane reductant effects this reduction for a wide variety of substrates, including pharmaceutically relevant structures, in good yields and with no overreduction to alcohols. Moreover, this methodology is scalable, allows access to deuterated aldehydes, and is also compatible with one-pot utilization of the aldehyde products.
Iosub, Andrei V.,Morav?ík, ?tefan,Wallentin, Carl-Johan,Bergman, Joakim
supporting information
p. 7804 - 7808
(2019/10/14)

Synthesis of α-Arylated Cycloalkanones from Congested Trisubstituted Spiro-epoxides: Application of the House-Meinwald Rearrangement for Ring Expansion
A three-step sequence for the synthesis of α-arylated cyclohexanones and the most challenging cycloheptanones is reported. First, an efficient one-pot synthesis of β,β'-disubstituted benzylidene cycloalkanes (styrenes) using the palladium-catalyzed Barluenga reaction from readily available feedstock chemicals is described. Furthermore, an epoxidation followed by the House-Meinwald rearrangement (HMR) of spiro-epoxides is reported to produce a number of α-arylated cycloalkanones upon ring expansion. Reactions catalyzed by bismuth triflate underwent quasi-exclusively ring expansion for all substrates (electronically poor and rich), with yields ranging from 15% to 95%, thus demonstrating the difficulty of achieving ring enlargement for electron-deficient spiro-epoxides. On the other hand, by means of catalysis with aluminum trichloride, the rearrangement of spiro-epoxides proceeded typically in high yields and with remarkable regioselectivity on a broader substrate scope. In this case, a switch of regioselectivity was achieved for spiro-epoxides with electron-withdrawing substituents which enable the method to be successfully extended to some chemospecific arene shifts and the synthesis of aldehydes bearing a α-quaternary carbon. While the HMR has been extensively studied for smaller ring enlargement, we are pleased to report herein that larger cyclohexanones and cycloheptanones can be obtained efficiently from more sterically demanding trisubstituted spiro-epoxides bearing electron-releasing and electron-neutral arene substituents.
Jeedimalla, Nagalakshmi,Jacquet, Camille,Bahneva, Diana,Youte Tendoung, Jean-Jacques,Roche, Stéphane P.
p. 12357 - 12373
(2018/09/06)

Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF3·Et2O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products
The regiocontrolled rearrangement of 1,2-diols has been achieved by controlling the loading of BF3·Et2O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.
Wang, Jun-Li,Li, Hui-Jing,Wang, Hong-Shuang,Wu, Yan-Chao
supporting information
p. 3811 - 3814
(2017/07/26)

Br?nsted Acid-Catalyzed Intramolecular Hydroarylation of β-Benzylstyrenes
Using triphenylmethylium tetrakis(pentafluorophenyl)borate as a convenient Br?nsted acid precatalyst, β-(α,α-dimethylbenzyl)styrenes are shown to cyclize efficiently to afford a variety of new indanes that possess a benzylic quaternary center. The geminal dimethyl-containing quaternary center is proposed to be necessary to arm the substrate for cyclization through steric biasing.
Cai, Xiao,Keshavarz, Amir,Omaque, Justin D.,Stokes, Benjamin J.
p. 2626 - 2629
(2017/05/24)

Pinacol Rearrangement and Direct Nucleophilic Substitution of Allylic Alcohols Promoted by Graphene Oxide and Graphene Oxide CO2H
Graphene oxide (GO) and carboxylic acid functionalized GO (GO–CO2H) have been found to efficiently promote the heterogeneous and environmentally friendly pinacol rearrangement of 1,2-diols and the direct nucleophilic substitution of allylic alcohols. In general, high yields and regioselectivities are obtained in both reactions using 20 wt % of catalyst loading and mild reaction conditions.
Gómez-Martínez, Melania,Baeza, Alejandro,Alonso, Diego A.
p. 1032 - 1039
(2017/03/27)

Synthesizing method of pentoxyverine drug intermediate 1-phenylcyclopentanecarboxylic acid
Provided is a synthesizing method of a pentoxyverine drug intermediate 1-phenylcyclopentanecarboxylic acid. The method comprises the following steps that 230 ml of sodium hydrogen sulfite solution and 0.15 mol of stannous chloride are added into a reaction vessel provided with a stirrer, a thermometer, a reflux condenser and a dropping funnel, the stirring speed is controlled to be 130-160 rpm, and the temperature of the solution is increased to 50-55 DEG C; 0.63 mol of phenylacetaldehyde (2) and 0.71-0.73 mol of 1,4-diaminobutane are slowly added, the temperature of the solution is increased to 60-65 DEG C, and stirring is continuously conducted for 8-9 h for reaction; 230 ml of potassium bromide solution is added, the temperature of the solution is decreased to 10-15 DEG C, oily liquid is dissolved out, the intermediate product is washed with propionitrile 7-9 times, the oily matter is added into 300 ml of cyclohexane solution, 130 ml of potassium bromide solution, 0.23 mol of cuprous chloride and 0.26 mol of potassium sulfite are added, the temperature of the solution is increased to 150-160 DEG C, and refluxing is conducted for 7-8 h; 2 L of sodium chloride solution is added, molecular sieve decoloring is conducted, filtering is conducted while the solution is hot, oxalic acid is added to filtrate to adjust the pH of the filtrate to be 1-2, a white solid is dissolved out, suction filtration is conducted, salt solution washing and toluene washing are conducted, dehydration is conducted through a dehydrating agent, recrystallization is conducted in nitromethane, and the crystal 1-phenylcyclopentanecarboxylic acid is obtained.
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(2017/03/14)

Protected amino hydroxy adamantane carboxylic acid and process for its preparation
Dipeptidyl peptidase IV (DP 4) inhibiting compounds are provided. The provided compounds can be used for treating diabetes and related diseases, especially Type II diabetes, and other diseases as set out herein, employing such DP 4 inhibitor or a combination of such DP 4 inhibitor and one or more of another antidiabetic agent such as metformin, glyburide, troglitazone, pioglitazone, rosiglitazone and/or insulin and/or one or more of a hypolipidemic agent and/or anti-obesity agent and/or other therapeutic agent.
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(2015/11/24)

Oxadiazoanthracene compounds for the treatment of diabetes
The present invention provides methods of use of oxadiazoanthracene derivatives of the formula (I) and pharmaceutically acceptable salts thereof, wherein A, B, C, R, R1, R2, R3, R4 and R5 are as herein described, and wherein said methods of use include uses for the treatment of disorders and diseases, such as diabetes.
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(2015/09/23)

Dihydroxypyrimidine carbonic acid derivatives and their use in the treatment, amelioration or prevention of a viral disease
The present invention relates to a compound having the general formula (Di), (Dii), or (Diii), optionally in the form of a pharmaceutically acceptable salt, solvate, polymorph, codrug, cocrystal, prodrug, tautomer, racemate, enantiomer, or diastereomer or mixture thereof, which are useful in treating, ameloriating or preventing a viral disease. Furthermore, specific combination therapies are disclosed.
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(2014/02/16)

PYRIMIDONE DERIVATIVES AND THEIR USE IN THE TREATMENT, AMELIORATION OR PREVENTION OF A VIRAL DISEASE
The present invention relates to a compound having the general formula (I), optionally in the form of a pharmaceutically acceptable salt, solvate, polymorph, codrug, cocrystal, prodrug, tautomer, racemate, enantiomer, or diastereomer or mixture thereof, which are useful in treating, ameloriating or preventing a viral disease. Furthermore, specific combination therapies are disclosed.
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(2014/07/22)

Biarylphosphonite gold(I) complexes as superior catalysts for oxidative cyclization of propynyl arenes into indan-2-ones
Striking gold: A series of variously functionalized propynyl arenes was smoothly converted into indan-2-ones by a new gold(I)-catalyzed oxidative cyclization process. [LAu]NTf2 (Tf=trifluoromethanesulfonyl) is a superior catalyst both in terms of yield and kinetics for the present transformation. Copyright
Henrion, Guilhem,Chavas, Thomas E. J.,Le Goff, Xavier,Gagosz, Fabien
supporting information
p. 6277 - 6282
(2013/07/11)

An iron catalyzed regioselective oxidation of terminal alkenes to aldehydes
Fe(BF4)2·6H2O with pyridine-2,6-dicarboxylic acid and PhIO can efficiently catalyze the regioselective oxidation of terminal alkene derivatives to aldehydes under mild and benign reaction conditions.
Chowdhury, Abhishek Dutta,Ray, Ritwika,Lahiri, Goutam Kumar
supporting information; experimental part
p. 5497 - 5499
(2012/07/01)

Selective oxidation of terminal aryl and aliphatic alkenes to aldehydes catalyzed by iron(iii) porphyrins with triflate as a counter anion
[Fe(Por)CF3SO3] (Por = porphyrin dianion) can efficiently catalyze selective oxidation of terminal aryl alkenes and aliphatic alkenes to aldehydes in good to high yields under mild conditions.
Chen, Guo-Qiang,Xu, Zhen-Jiang,Zhou, Cong-Ying,Che, Chi-Ming
supporting information; experimental part
p. 10963 - 10965
(2011/11/06)

Silicon-(thio)urea Lewis acid catalysis
We present a new class of catalysts based on the combination of N,N′-diaryl(thio)ureas and weak silicon Lewis acids (e.g., SiCl 4). Such silicon-(thio)urea catalysts effectively catalyze the stereospecific rearrangement of epoxides to quaternary carbaldehydes.
Hrdina, Radim,Mueller, Christian E.,Wende, Raffael C.,Lippert, Katharina M.,Benassi, Mario,Spengler, Bernhard,Schreiner, Peter R.
supporting information; experimental part
p. 7624 - 7627
(2011/06/26)

Studies towards the taming of the 'carbocation' in the regioselective ring opening of epoxides to allylic alcohols
Regioselective isomerisation of epoxides to allylic alcohols can be achieved using p-toluenesulfonic acid in the presence of 1,3- dimethylimidazolidin-2-one. Georg Thieme Verlag Stuttgart.
Chapman, Helen A.,Herbal, Karim,Motherwell, William B.
experimental part
p. 595 - 598
(2010/09/15)

Efficient rearrangement of epoxides catalyzed by a mixed-valent iron trifluoroacetate [Fe3O(O2CCF3)6(H2O)3]
The mixed-valent oxo-centered triiron(III, III, II) trifluoroacetate complex [Fe2IIIFeIIO(O2CCF3)6(H2O)3] was prepared by reacting anhydrous iron(III) chloride with boiling trifluoroacetic acid under nitrogen. The non-hygroscopic and readily available mixed-valent triiron trifluoroacetate complex was found to be an efficient catalyst for the regioselective rearrangement of epoxides. A number of carbonyl compounds formed via the rearrangement of epoxides could be obtained by a simple filtration of the reaction mixture through a short plug of silica gel.
Ertürk, Erkan,G?llü, Mehmet,Demir, Ayhan S.
experimental part
p. 2373 - 2377
(2010/06/16)

Gold-catalyzed double migration-benzannulation cascade toward naphthalenes
(Chemical Equation Presented) A novel gold(I)-catalyzed cycloisomerization of propargylic esters leading to unsymmetrically substituted naphthalenes has been developed. This cascade reaction involves an unprecedented tandem sequence of 1,3- and 1,2-migration of two different migrating groups. It is believed that this transformation likely proceeds via the formation of 1,3-diene intermediate or its precursor, which upon cyclization and aromatization steps transforms into the naphthalene core. 2008 American Chemical Society.
Dudnik, Alexander S.,Schwier, Todd,Gevorgyan, Vladimir
supporting information; body text
p. 1465 - 1468
(2009/04/10)

Highly regio- and stereoselective rearrangement of epoxides to aldehydes catalyzed by high-valent metalloporphyrin complex, Cr(TPP)OTf
Chromium(III) tetraphenylporphyrin triflate, Cr(TPP)OTf, works as an efficient and characteristic Lewis acid catalyst in the regio- and stereoselective rearrangement of epoxides to aldehydes. This Cr(TPP)OTf-catalyzed reaction is an operationally simple a
Suda, Kohji,Kikkawa, Taketoshi,Nakajima, Shin-Ichiro,Takanami, Toshikatsu
p. 9554 - 9555
(2007/10/03)

Reactions of a β-sultam ring with Lewis acids via the C-S bond cleavage
Selective C-S bond cleavage of a β-sultam ring was achieved by the reactions with Lewis acids. Aryl ketones or aldehyde were provided from 3- aryl-β-sultams whereas β-sultams bearing a poorly migratory substituent at C-3 gave trans-1,2,3-oxathiazolidine 2-oxides and/or cis-aziridines. These reactions were influenced by the cation-stabilizing capability of C-4 substituents and by the configuration of the substituents at C-3 and C-4. Some 4-alkenyl-3-aryl-β-sultams underwent tandem intramolecular cyclization to give bicyclo[3.2.1]- and [2.2.1]-γ-sultams via the processes of C-S bond cleavage, 1,2-aryl shift, cation-olefin cyclization and recombination of the sulfonyl anion.
Iwama, Tetsuo,Ogawa, Miyoko,Kataoka, Tadashi,Muraoka, Osamu,Tanabe, Genzoh
p. 8941 - 8974
(2007/10/03)

1-substituted, 3-carboxylic acid piperidine derivatives
The present invention relates to therapeutically active azaheterocyclic compounds, a method of preparing the same and to pharmaceutical compositions comprising the compounds. The novel compounds are useful in treating a central nervous system ailment related to the GABA uptake.
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(2008/06/13)

Lewis Acid-Promoted Selective Rearrangement of Trisubstituted Epoxides to Aldehydes or Ketones
Rearrangement of trisubstituted epoxides has been effected under the influence of various Lewis acids.Among these, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) can be selectively rearranged from trisubstituted epoxides to aldehydes, while
Maruoka, Keiji,Murase, Noriaki,Bureau, Ronan,Ooi, Takashi,Yamamoto, Hisashi
p. 3663 - 3672
(2007/10/02)

A Facile Workup-Free Catalytic Rearrangement of Epoxides on Immobilized Organoaluminum Columns
The immobilized organoaluminum columns can be successfully utilized as a workup-free reactor for the catalytic rearrangement of various epoxides to carbonyl compounds.
Nagahara, Shigeru,Maruoka, Keiji,Yamamoto, Hisashi
p. 1193 - 1196
(2007/10/02)

Organoaluminum-catalyzed rearrangement of epoxides a facile route to the synthesis of optically active β-siloxy aldehydes
A new, stereocontrolled rearrangement of epoxy silyl ethers leading to β-siloxy aldehydes has been effected with stoichiometric use of exceptionally bulky, oxygenophilic methylaluminum bis(4-bromo-2,6-di-trert-butylphenoxide) (MABR) under mild conditions. Used in combination with the Sharpless asymmetric epoxidation of allylic alcohols, this rearrangement represents a new approach to the synthesis of various optically active β-hydroxy aldehydes, useful intermediates in natural product synthesis. The modified organoaluminum reagent, MABR is also applicable to the transformation of a variety of simple epoxides to carbonyl compounds with high efficiency and selectivity. Further, the catalytic version for the rearrangement of epoxy silyl ethers as well as simple epoxides has been newly devised. The scope and limitation of this catalytic method has been clarified with various epoxy substrates.
Maruoka, Keiji,Ooi, Takashi,Nagahara, Shigeru,Yamamoto, Hisashi
p. 6983 - 6998
(2007/10/02)

SUBSTITUENT EFFECTS ON THE REGIO- AND STEREOSELECTIVITY OF GAS-PHASE ACID-INDUCED RING OPENING IN 1-ARYLCYCLOHEXENE OXIDES
Comparative analysisof the ratio of the isomeric monomethyl ethers of 1-arylcyclohexane-1,2-diols formed in the gas-phase and solvolytic acid-induced methanolysis of several 1-arylcyclohexene oxides indicates the intrinsic electronic factors detrminimg the regio- and stereochemical course of the nucleophilic attack, related to the partial degree of carbocationic character at the reaction centre in the substitution transition state.
Cecchi, P.,Pizzabiocca, A.,Renzi,G.,Chini, M.,Crotti, P.,et al.
p. 4227 - 4234
(2007/10/02)

Organoaluminum-Promoted Rearrangement of Epoxy Silyl Ethers to β-Siloxy Aldehydes
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Maruoka, Keiji,Ooi, Takashi,Yamamoto, Hisashi
p. 6431 - 6432
(2007/10/02)

KINETIC RESOLUTION OF EPOXIDES BY CHIRAL ORGANOALUMINIUM CALTALYST SHORT SYNTHESIS OF (-)-C16 JUVENILE HORMONE
The use of chiral organoaluminium reagent as a catalyst to resolve simple ketoepoxides is explored.The optically pure ketoepoxide 10 was recovered after 80percent conversion.The recovered pure epoxides is a useful chiral building block in the synthesis of
Naruse, Yuji,Esaki, Toru,Yamamoto,Hisashi
p. 4747 - 4756
(2007/10/02)

Synthesis of aldehydes and products of such synthesis
The disclosure describes the production of complex aliphatic, unsaturated and cycloalkane aldehydes utilizing heterocyclic ring compounds, such as oxazines, particularly dihydro-1,3-oxazines. The oxazines are treated with an alkali metal-alkane compound, such as butyl lithium in the presence of an organic solvent at subzero temperature to form an anion of the oxazine. This anion is then alkylated in the anhydrous reaction mixture by introduction of a suitable halide, epoxide or ketone while still at a subzero temperature and mixture is permitted to warm up to room temperature, following which the reaction mixture is acidified, as with hydrochloric acid to pH 2 to 3, extracted and then made basic, as with caustic alkali with cooling. The reaction mixture is then extracted, as with ether, to produce after evaporation the alkylated dihydro-1,3-oxazine. The alkylated dihydro-1,3-oxazine is then reacted with an alkali metal or sodium borohydride or borodeuteride or borotritide, with cooling to subzero temperatures at about a neutral pH and then transferred into a basic aqueous environment following extraction of the aqueous layer with an organic solvent, such as ether, to give a tetrahydro-1,3-oxazine. This compound may then be converted to the aldehyde desired by steam distillation or by hydrolysis in the presence of a dilute or weak acid, such as hydrochloric or oxalic acid. The aldehydes may then be extracted. These aldehydes are useful as components or intermediates in flavoring or perfumes, in insect attractants and repellants, and in pharmaceuticals.
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(2008/06/13)