cas 928-90-5, 5-Hexyn-1-ol | Articles data

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Synthesis of α,β-unsaturated epoxy ketones utilizing a bifunctional sulfonium/phosphonium ylide
Herein, a new protocol for rapid synthesis of α,β-unsaturated epoxy ketones utilizing a bifunctional sulfonium/phosphonium ylide is described. This approach comprises two sequential chemoselective reactions between sulfonium and phosphonium ylides and two distinct aldehydes, which allows for the rapid construction of a variety of unsymmetric α,β-unsaturated epoxy ketones. This methodology allows the rapid construction of the core reactive functionality of a family of lipid peroxidation products, the epoxyketooctadecenoic acids, but can be further broadly utilized as a useful synthon for the synthesis of natural products, particularly those derived from oxidized fatty acids. Accordingly, a protocol utilizing this approach to synthesize the epoxyketooctadecenoic acid family of molecules is described.
Eskandari, Roozbeh,Hess, Jeremy P.,Tochtrop, Gregory P.
supporting information
p. 7136 - 7139
(2021/07/28)

Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O-H and N-H Additions
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization of the alkyne that leads to preferential heteroatom attack at the more electron-deficient carbon. The electronic effects are studied in other contexts, including hydroacyloxylation and hydroamination, and similar trends in directionality are predominant although not uniformly observed.
Costello, Jeff P.,Ferreira, Eric M.
supporting information
p. 9934 - 9939
(2019/12/24)

Enantioselective Rhodium-Catalyzed Dimerization of ω-Allenyl Carboxylic Acids: Straightforward Synthesis of C2-Symmetric Macrodiolides
Herein, we report on the first enantioselective and atom-efficient catalytic one-step dimerization method to selectively transform ω-allenyl carboxylic acids into C2-symmetric 14- to 28-membered bismacrolactones (macrodiolides). This convenient asymmetric access serves as an attractive route towards multiple naturally occuring homodimeric macrocyclic scaffolds and demonstrates excellent efficiency to construct the complex, symmetric core structures. By utilizing a rhodium catalyst with a modified chiral cyclopentylidene-diop ligand, the desired diolides were obtained in good to high yields, high diastereoselectivity, and excellent enantioselectivity.
Steib, Philip,Breit, Bernhard
supporting information
p. 6572 - 6576
(2018/05/08)

Self-assembly and solid-state polymerization of butadiyne derivatives with amide and trialkoxyphenyl groups
Three butadiyne derivatives with amide and tri(dodecyloxy)-phenyl (TDP) groups were synthesized, and four solidification methods were applied to obtain their self-assembling states in various conditions. The solids obtained were characterized by the solid-state polymerization behaviors, stretching vibration wavenumbers of N-H bonds of amide groups, powder X-ray diffraction, the thermal behaviors, and scanning electron microscope (SEM) observations. We found that all compounds had at least two polymorphs. Property differences between two polymorphs depended on the compounds. Two compounds showed clear differences in UV-vis spectra of the photo-polymerized solids, i.e., the polydiacetylene (PDA) structure, and irregularly polymerized form, or two PDA structures. The remaining compound showed the same PDA absorption but the monomer melting points were different. All compounds gave the gels in various organic solvents because of the molecular design with amide and TDP groups. SEM observation clarified the relationship between gel appearance and the nanostructures.
Kikuchi, Kohei,Tatewaki, Yoko,Okada, Shuji
supporting information
p. 298 - 305
(2017/05/10)

Synthesis and solid-state polymerization of a macrocyclic compound with two butadiyne units
A macrocyclic compound 1 with two butadiyne and four dodecyloxy-substituted benzamide moieties was successfully synthesized, and its ring structure was confirmed by the MALDI-TOF mass spectra and the 1HNMR spectra. Compound 1 showed two modifications depending on solvent for the solidification. Characteristic excitonic absorption bands of polydiacetylene were observed at around 500 nm for one of the modifications after UV irradiation. Quantitative conversion of butadiyne moieties to the corresponding polydiacetylene structure was confirmed by the Raman spectra.
Kikuchi, Kohei,Tatewaki, Yoko,Okada, Shuji
p. 387 - 394
(2017/06/14)

Syntheses and biological evaluation of 1,2,3-triazole and 1,3,4-oxadiazole derivatives of imatinib
Three novel series of 1,2,3-triazole and 1,3,4-oxadiazole derivatives of imatinib were prepared and evaluated in vitro for their cytostatic effects against a human chronic myeloid leukemia (K562), acute myeloid leukemia (HL60), and human leukemia stem-like cell line (KG1a). The structure-activity relationship was analyzed by determining the inhibitory rate of each imatinib analog. Benzene and piperazine rings were necessary groups in these compounds for maintaining inhibitory activities against the K562 and HL60 cell lines. Introducing a trifluoromethyl group significantly enhanced the potency of the compounds against these two cell lines. Surprisingly, some compounds showed significant inhibitory activities against KG1a cells without inhibiting common leukemia cell lines (K562 and HL60). These findings suggest that these compounds are able to inhibit leukemia stem-like cells.
Li, Yong-Tao,Wang, Jing-Han,Pan, Cheng-Wen,Meng, Fan-Fei,Chu, Xiao-Qian,Ding, Ya-Hui,Qu, Wen-Zheng,Li, Hui-Ying,Yang, Cheng,Zhang, Quan,Bai, Cui-Gai,Chen, Yue
p. 1419 - 1427
(2016/02/19)

Sustainable, mild and efficient p-methoxybenzyl ether deprotections utilizing catalytic DDQ
A procedure for the selective deprotection of p-methoxybenzyl ethers using catalytic amounts of DDQ and of sodium nitrite, with oxygen as the terminal oxidant, is reported.
Walsh, Katie,Sneddon, Helen F.,Moody, Christopher J.
p. 7380 - 7387
(2017/09/13)

A convenient approach for the deprotection and scavenging of the PMB group using POCl3
A convenient and high yielding approach for the deprotection and scavenging of the p-methoxybenzyl (PMB) group in PMB ethers and PMB esters was developed using POCl3 as the reagent. 4-Methoxybenzyl chloride, a starting material used for the preparation of PMB ethers and esters was regenerated in the deprotection step. This mild and selective procedure tolerates several acid sensitive functional groups. The Royal Society of Chemistry 2013.
Ilangovan, Andivelu,Saravanakumar, Shanmugasundar,Malayappasamy, Subramani,Manickam, Govindaswamy
p. 14814 - 14828
(2013/09/02)

Maltoside and Phosphocholine Derivatives, Uses thereof and Methods of Preparing Artificial Lipid Structures Thereof
Disclosed are saccharide and phosphocholine derivatives. The derivatives include azide and alkyne derivatives which form one end of a variable length carbon chain. The opposite end of the variable length carbon chain is covalently linked to the saccharide or phosphocholine. The saccharide may be, for instance, a maltoside. The alkyne and azide derivatives of the saccharides and phosphocholine may be reacted together to form amphiphilic molecules useful in cellular membrane studies and applications. By adjusting the length of the carbon chain, the biochemical and biophysical properties of the resultant 1,4-disubstituted 1,2,3-triazole compounds may be custom tailored for the intended application. Resultant molecules may form micelles, bicelle, lipid bilayers and other like structures useful in the isolation and purification of membrane bound or membrane associated proteins and biochemical components. The saccharides and phosphocholine molecules may be alternatively substituted as desired to provide additional flexibility in designing the desired end product.
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(2013/04/24)

Tetris in monolayers: Patterned self-assembly using side chain shape
The "kinked" shapes of conjugated alkadiynes constrain chain packing in monolayers on HOPG. Centrally located diyne units permit assembly of 1,5-bis(alkadiyne)anthracene monolayers. Off-center diynes inhibit self-assembly. Shape matched pairs of off-center diyne chains direct self-assembly of compositionally patterned, two component monolayers.
Xue, Yi,Zimmt, Matthew B.
supporting information; experimental part
p. 8832 - 8834
(2011/09/16)

Phase separation as a strategy toward controlling dilution effects in macrocyclic glaser-hay couplings
Macrocycles are abundant in numerous chemical applications, however the traditional strategy for the preparation of these compounds remains cumbersome and environmentally damaging; involving tedious reaction set-ups and extremely dilute reaction media. The development of a macrocyclization strategy conducted at high concentrations is described which exploits phase separation of the catalyst and substrate, as a strategy to control dilution effects. Sequestering a copper catalyst in a highly polar and/or hydrophilic phase can be achieved using a hydrophilic ligand, T-PEG1900, a PEGylated TMEDA derivative. Similarly, phase separation is possible when suitable copper complexes are soluble in PEG400, a green and efficient solvent which can be utilized in biphasic mixtures for promoting macrocyclization at high concentrations. The latter phase separation technique can be exploited for the synthesis of a wide range of industrially relevant macrocycles with varying ring sizes and functional groups.
Bedard, Anne-Catherine,Collins, Shawn K.
supporting information; experimental part
p. 19976 - 19981
(2012/01/13)

Indium triiodide catalyzed direct hydroallylation of esters
The InI3-catalyzed hydroallylation of esters by using hydroand allysilanes under mild conditions has been accomplished. Many significant groups such as alkenyl, alkynyl, cyano, and nitro ones survive under these conditions. This reaction system, provided routes to both homoallylic alcohols and ethers, in which either elimination of the alkoxy moiety or of the carbonyl oxygen atom could be freely selected by changing the substituents on the alkoxy moiety and on the hydrosilane. In addition, the hydroallylation of lactones took place without ring cleavage to produce the desired cyclic ethers in high yields.
Nishimoto, Yoshihiro,Inamoto, Yoshihiro,Saito, Takahiro,Yasuda, Makoto,Baba, Akio
supporting information; experimental part
p. 3382 - 3386
(2010/08/19)

Isolable gold(I) complexes having one low-coordinating ligand as catalysts for the selective hydration of substituted alkynes at room temperature without acidic promoters
Hydration of a wide range of alkynes to the corresponding ketones has been afforded in high yields at room temperature by using gold(I)-phosphine complexes as catalyst, with no acidic cocatalysts required. Suitable substrates covering alkyl and aryl terminal alkynes, enynes, internal alkynes, and propargylic alcohols, including enantiopure forms, are cleanly transformed to the corresponding ketones in nearly quantitative yields. Acid-labile groups present in the substrates are preserved. The catalytic activity strongly depends on both the nature of the phosphine coordinated to the gold (I) center and the softness of the counteranion, the complex AuSPhOsNTf2 showing the better activity. A plausible mechanism for the hydration of alkynes through ketal intermediates is proposed on the basis of kinetic studies. The described catalytic system should provide an efficient alternative to mercury-based methodologies and be useful in synthetic programs.
Leyva, Antonio,Corma, Avelino
scheme or table
p. 2067 - 2074
(2009/08/07)

Synthesis and solid-state polymerization of triyne and enediyne derivatives with similar π-conjugated structures
Three diacetylene monomer model compounds with similar π-conjugation systems, 10-phenyl-5,7,9-decatriynyl W-phenylcarbamate (1), (E)-10-phenyldec-9- en-5,7-diynyl /V-phenylcarbamate (2), and (E)-10-phenyldec-5-en-7,9-diynyl N-phenylcarbamate (3), were synthesized and their properties and solid-state polymerization were investigated. Based on the absorption spectra of the monomers, it was found that the conjugation effect of a double bond was different from that of a triple bond in solution. Monomers 1,2, and 3 gave one, two, and five crystal forms, respectively, of which 1 and one of the crystal forms of 2 (2a) could be polymerized in the solid state. The conversions after y-ray irradiation (1 MGy dose) were 53% and 20%, respectively. The longest-wavelength absorption maxima of the polymers prepared from 1 and 2a were 645 and 655 nm, respectively. The polymerizable crystals 1 and 2a were found to have layered monomer structures with spacing of 3.1-3.6 nm. Based on solid-state 13CNMR spectra, the polymerization sites of 1 were determined to be the 1,4- and 3,6-positions with respect to the phenyl ring, and that of 2a was determined to be the 3,6-position with respect to the phenyl ring.
Mizukoshi, Kana,Okada, Shuji,Kimura, Tatsumi,Shimada, Satoru,Matsuda, Hiro
experimental part
p. 1028 - 1037
(2009/04/13)

Efficient synthesis of 8,11-dimethylene-bicyclo[5.3.1]undecan-2-one
We report here, an effective methodology for the preparation of 8,11-dimethylene-bicyclo[5.3.1]undecan-2-one. The key steps in these reactions were chloromethylation, cationic-alkyne cyclization and anionic fragmentation sequence.
Gu, Haining,Xu, Wei Ming,Kinstle, Thomas H.
p. 6449 - 6451
(2007/10/03)

20-HETE antagonists and agonists
20-HETE agonists and antagonists are disclosed along with therapeutic applications. In a preferable form of the invention, the 20-HETE agonists are selected from the group consisting of 21-hydroxyheneicosa-5(Z), 8(Z),11(Z),14(Z)-tetraenoic acid, 20-hydroxyeicosa-5(Z),14(Z)-dienoic acid and 20-,21-dimethyl 20-HETE. Preferable 20-HETE antagonists include 5(S)-HETE, 15(S)-HETE, 19(S)-HETE, 19-hydroxynonadeca-5(Z),8(Z),11(Z),14(Z)-tetraenoic acid and 20-hydroxyeicosa 6(Z),15(Z)-dienoic acid.
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(2008/06/13)

Study of the regioselectivity in the hydrotelluration of hydroxy alkynes
Vinylic tellurides were synthesized by the addition of organotellurols to acetylenic alcohols and the regioselectivity of the reaction was evaluated.
Stefani, Hélio A.,Cardoso, Lincoln D. G.,Valduga, Claudéte J.,Zeni, Gilson
p. 167 - 172
(2007/10/03)

Acid-catalyzed cyclization of vinylsilanes bearing a hydroxy group: A new method for stereoselective synthesis of disubstituted tetrahydrofurans
In the presence of a catalytic amount of TsOH or TiCl4, (Z)-5-silyl-4-penten-1-ols ((Z)-1) are smoothly cyclized to 2-silylmethyl-substituted tetrahydrofurans. This cyclization is applicable to the construction of a tetrahydropyran ring. The silyl group and the geometry of the C-C double bond strongly influence the cychzation rate. TBDMS and benzyldimethylsilyl groups considerably accelerate the cyclization in comparison with a dimethylphenylsilyl group, and (E)-vinylsilanes show much lower reactivity than the corresponding (Z)-isomers. The cyclization proceeds by stereospecific syn addition of the hydroxy group. Vinylsilanes 17, 19, and 21, (Z)-5-silyl-4-penten-1-ols bearing a substituent on the methylene tether, smoothly undergo the acid-catalyzed cyclization to give trans-2,5-, cis-2,4-, and trans-2,3-disubstituted tetrahydrofurans, respectively, with moderate to high stereoselectivity. The silyl group of some cychzed products can be easily converted into a hydroxy group with stereochemical retention.
Miura,Okajima,Hondo,Nakagawa,Takahashi,Hosomi
p. 11348 - 11357
(2007/10/03)

Microwave thermolysis V : A rapid and selective method for the cleavage of THP ethers, acetals and acetonides using clay supported ammonium nitrate 'Clayan' in dry media
The deprotection of a variety of tetrahydropyranyl ethers (THP), acetonides and acetals into their parent compounds using clay supported ammonium nitrate 'Clayan' under microwave irradiation is described. The ecofriendly nature of the reagent and non solvent conditions are the important features of the procedure.
Meshram,Sumithra,Reddy,Ganesh,Yadav
p. 2807 - 2815
(2007/10/03)

Stereoselective total syntheses of 9(S)- and 9(R)-HETE
A simple and efficient stereoselective total synthesis of methyl 9(S)- and 9(R)-hydroxy -5(Z), 7(E), 11(Z), 14(Z)-eicosatetraenoates using base induced opening of chiral 2.3-epoxy chlorides is described.
Yadav,Bhanu,Dutta, Dinah
p. 3929 - 3934
(2007/10/03)

A large scale and concise synthesis of γ-linolenic acid from 4- chlorobut-2-yn-1-ol
A large scale and concise synthesis of γ-linolenic acid is described. The key step of the synthesis involves a copper salt mediated cross-coupling of two different alkynes and chlorobutynol.
Durand, Sandrine,Parrain, Jean-Luc,Santelli, Maurice
p. 1015 - 1018
(2007/10/03)

A Stereoselective Synthesis of 8(R) and 8(S), 11(R),12(S)-Trihydroxyeicosa-5(Z),9(E),14(Z)-Trienoic Acid from 2-Deoxy-D-Ribose
A stereoselective synthesis of stereoisomers of the title compound from 2-deoxy-D-ribose using reductive elimination protocol as the key step is described.
Yadav, J. S.,Vadapalli, Prahlad
p. 641 - 644
(2007/10/02)

SYNTHESE ET REACTIVITE DE SILANES PROPARGYLIQUES ω-FONCTIONNELS : PREPARATION DE VINYLIDENE-3 OXOLANNES, OXANNES, OXEPANNES ET OXOCANNES
The ω-silyloxypropargyltrimethylsilanes regiospecifically react with aliphatic and aromatic aldehydes to lead to vinylidene oxigen-containing heterocycles, such as 3-vinylidene oxolanes, oxanes, oxepanes and oxocanes.
Pornet, J.,Damour, D.,Miginiac, L.
p. 2017 - 2024
(2007/10/02)

SHORT INTRAMOLECULAR DIELS-ALDER APPROACH TO FUNCTIONALIZED SPIRODECANES
The intramolecular Diels-Alder reaction of a (5'-hexynyl)cyclopentadiene provides a 1,2-tetramethylene-bridged norbornadiene which undergoes selective monohydrogenation followed by ozonolysis to provide the title compounds.
Nystroem, Jan-E.,McCanna, Terrence D.,Helquist, Paul,Iyer, Ramnath S.
p. 5393 - 5396
(2007/10/02)

VINYL CATIONS. 40. pi - AND sigma -ROUTES TO VINYL CATIONS. SOLVOLYSES OF 2-METHYLCYCLOHEXENYL, CYCLOPENTYLIDENEETHYL, HEX-5-YN-1-YL, AND RELATED TRIFLATES.
Three triflates were solvolyzed at various temperatures in water-alcohol mixtures, in TFE-water mixtures, in TFA, in TFIP, in HFIP, and in 100% TFE in the presence of various buffers and the resulting products were determined. The three reactants were also solvolyzed in a standard mixture (1:100:100 equals triflate:TFE:Na//2CO//3) at various temperatures, and the yields of products were compared. The solvolysis products were shown to be under kinetic control.
Hanack,Fuchs,Collins
p. 4008 - 4017
(2007/10/12)

STEREOSPECIFIC SYNTHESIS OF (Z)-13-HEXADECEN-11-YN-1-YL ACETATE THE SEX PHEROMONE OF THE PROCESSIONARY MOTH, AND OF (5Z,7E)-5,7-DODECADIEN-1-OL, A SEX PHEROMONE COMPONENT OF THE FOREST TENT CATERPILLAR
(Z)-13-hexadecen-11-yn-1-yl acetate (2), the sex pheromone of Thaumetopoea pytyocampa, and (5Z,7E)-5,7-dodecadien-1-ol (3), sex pheromone component of Malacosoma disstria, have been prepared in high chemical and stereoisomeric purity by synthetic schemes involving the stereospecific coupling of ω-functionalized 1-alkynes with (Z)- or (E)-1-iodo-1-alkenes in the presence of a catalytic amount of (PPh3)4Pd and CuI, under phase transfer conditions.
Rossi, Renzo,Carpita, Adriano
p. 287 - 290
(2007/10/02)

Preparations et essais d'heterocyclisation radicalaire de nitrites et N-chloroamines acetyleniques
Nitrites RCC(CH2)nONO and N-chloroamines RCC(CH2)nN(Et)Cl (n = 3,4; R = H,Ph,Me) have been treated so as to form the corresponding heteroatomic radicals.In the case of nitrites, a product resulting from intramolecular addition of the alkoxy radical to the triple bond could be isolated only for n = 3.This product, which was obtained with a very poor yield, is the γ-butyrolactone resulting from decomposition of a primary product not isolated.When n = 4 and R = H, an isoxazole which could derive from an initial step consisting of the intramolecular abstraction of a propargylic hydrogen was formed.With acetylenic N-chloramines, we could not identify any product resulting from intramolecular addition of an aminyl radical to the triple bond.These rather poor synthetic results are compared to the much better ones obtained by intramolecular addition of the thiyl radical to the acetylenic system, and the origin of this difference in behaviour is discussed.
Dupuy, Claude,Surzur, Jean-Marie
p. 374 - 380
(2007/10/02)

Reactions involving carbon tetrahalides and α-methyl ketones or ketones having α,α'-hydrogens
A process for preparing aldehydes, ketones, carboxylic acids and esters by reaction of various substrates with carbon tetrahalides in the presence of a strong base. The reactions are accelerated by the presence of a polar solvent. Anions of the substrate attack the carbon tetrahalide to produce a halogenated intermediate and a dihalocarbene. The halogenated intermediate reacts with the base to form the indicated products. By the reactions of this process, primary alcohols are converted to aldehydes, carboxylic acids and esters, secondary alcohols are converted to ketones and ketones having an α-methyl group or both α and α' hydrogens are converted to carboxylic acids and esters. Non α-methyl ketones having α but no α' hydrogens are simply α-halogenated. The dihalocarbene generated in the reaction may attack the product, solvent, or another substrate to form other products.
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(2008/06/13)