Fe-catalyzed synthesis of (4Z)-alkenoates

Russian Journal of General Chemistry - A new approach to stereoselective synthesis of (4Z)-alkenoates has been developed based on Fecatalyzed cross-coupling of ethyl (4Z)-5-chloropent-4-enoate with...     

Synthesis of (Z)-4-hydroxytamoxifen and (Z)-2-[4-[1-(p-hydroxyphenyl)-2-phenyl]-1butenyl]phenoxyacetic acid

The synthesis of (Z)-4-hydroxytamoxifen and (Z)-2-[4-[1-(p-hydroxyphenyl)-2-phenyl]-1-butenyl]phenoxyacetic acid was accomplished using a McMurry reaction as the key step. The perfluorotolyl derivatives of the McMurry products enabled the separation of the minor undesirable geometrical isomer. The methodology proceeds without E,Z isomerization, employs a very mild final debenzylation step compatible with a large array of functional groups, and can be applied to the generation of a variety of 4-hydroxytamoxifen analogues.     

Synthesis and Crystal Structure of (Z)-Ethyl-4-(4-methoxy)benzylidene-2-(3,5-dimethoxypheny-tetrahydrofuran-3,3-dicarboxylate

The title compound (Z)-ethyl-4-(4-methoxy)benzylidene-2-(3,5-dimethoxyphenyl)- tetrahydrofuran-3,3-dicarboxylate has been synthesized, and its crystal structure was characterized by X-ray single-crystal diffraction. The crystal belongs to triclinic, space group P1-, with a = 8.140(3), b = 11.966(4), c = 13.771(5) α = 67.366(4), β = 85.165(5), γ = 75.806(4)°, V = 1200.1(7) 3, Z = 2, C26H30O8, Mr = 470.50, Dc = 1.302 g/cm3, F(000) = 500, λ(MoKα) = 0.71073 , μ = 0.096 mm–1, R = 0.0659 and wR = 0.1841 for 3080 observed reflections (I > 2σ(I)). As a key intermediate of HIV-1 integrase inhibitor, the synthesis and structure confirmation of the title compound are important for further studies.     

DIASTEREOSELECTIVE SYNTHESIS AND STEREOCHEMISTRY OF (Z)-1-[3-ARYL-2-(PHENYLSULFANYL)-2-OXIRANYL]-1-ETHANONES

Diastereoselective synthesis of a series of (Z)-1-[3-aryl-2-(phenylsulfanyl)-2-oxiranyl]-1-ethanones was effected from the reaction of (Z)-4-aryl-3-(phenylsulfanyl)-3-buten-2-ones with alkaline hydrogen peroxide in tetrahydrofuran. The stereochemistry of the oxiranes has been deduced from two-dimensional NOESY spectrum.     

A new route to the synthesis of (E)- and (Z)-2-alkene-4-ynoates and nitriles from vic-iiodo-(E)-alkenes catalyzed by Pd(0) nanoparticles in water

An efficient procedure for the stereoselective synthesis of (E)- and (Z)-2-alkene-4-ynoates and -nitriles by a simple reaction of vic-diiodo-(E)-alkenes with acrylic esters and nitriles catalyzed by in situ prepared Pd(0) nanoparticles in water has been developed. Addition of acrylic esters leads to (E)-isomers exclusively, whereas (Z)-isomers are obtained in high stereoselectivity from reactions of acrylonitrile. The aqueous slurry of Pd nanoparticles is recycled. A probable mechanism has been suggested.     

Synthesis and antifungal activity of (-)-(Z)-dysidazirine

A short, flexible synthesis of the marine natural product (2 R)-(Z)-dysidazirine (-)-1 has been completed. (-)-1 shows significant antifungal activity across a panel of seven human pathogens, whereas the structural analogue (-)-2, featuring a terminal tert-butyl group, is essentially inactive.     

Stereoselective Synthesis of (Z)-2-Acylamido-4-phenylcrotonates

Stereospecificsynthesisof(Z)-a,o-dehydroaminoacidsisofgreatimportanceinthepreparationofuncommonornatUralopticallypureaminoacids,because,ingeneral,(Z)-isomersaffordmuchhigherenantioselectivitieswithfasterratesthan(E)-isomersinthecatalyticasymmetrichydrogenation'.(Z)-isomersofethyl2-acylamido-4-phenylcrotonate2areimpoFtantprecursorsinthecourseofoursynthesisofL-homopheny1alaninel,akeysynthonformostcommerciallyimportantantihypertensiveACEinhibitorssuchasEnalapril,Benazepril,Lisinopril.Hereinwe…     

5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮的合成

报道俘精酸酐类化合物(E/Z)4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2,5-酮的拆分,及(E)和(Z)-5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2,5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮4(E)和4(Z)的合成,并对它们的光致变色特性进行了初步研究。     

Palladium-catalyzed heteroannulation leading to heterocyclic structures with two heteroatoms: a highly regio- and stereoselective synthesis of (Z)-4-alkyl-2-alkyl(aryl)idene-3,4-dihydro-2H-1,4-benzoxazines and (Z)-3-alkyl(aryl)idene-4-tosyl-3,4-dihydro-2H-1,4-benzoxazines.

A highly convenient method has been developed for the synthesis of (Z)-4-alkyl-2-alkyl(aryl)idene-3,4-dihydro-2H-1,4-benzoxazines 9 and (Z)-3-alkyl(aryl)idene-4-tosyl-3,4-dihydro-2H-1,4-benzoxazines 34-38 through palladium-copper-catalyzed reactions. Aryl halides 7 reacted with 2-[N-alkyl(benzyl)-N-prop-2'-ynyl]aminophenyl tosylate 6 in the presence of (PPh3)2PdCl2 (3 mol %), CuI(5 mol %) in triethylamine at room temperature to yield 2-[N-alkyl(benzyl)-N-(3-aryl-prop-2'-ynyl)]-aminophenyl tosylates 8 in extremely good yields (72-96%). The latter could then be cyclized with KOH in ethanol-water to Z-9 in a highly regio- and stereoselective manner. Similarly, palladium-copper-catalyzed reaction of 2-(prop-2'-ynyloxy)aniline (21) with aryl iodides 7 led to 22-26 which after tosylation and cyclization with cuprous iodide in CH3CN in the presence of K2CO3 and Bu4-NBr led to the (Z)-3-alkyl(aryl)idene-4-tosyl 3,4-dihydro-2H-1,4-benzoxazines 34-38 in good overall yields. The Z-stereochemistry of the products was established from 1H NMR spectra, 3JCH values (between vinylic proton and methylenic carbon of the heterocyclic ring), NOE experiments, and X-ray analysis. The method was also found to be suitable for the synthesis of bis(benzoxazinylated) derivatives 17, 39, and 2-alkyl-3,4-dihydro-2H-1,4-benzoxazines 18. Our method for the synthesis of 3,4-dihydro-2H-1,4-benzoxazines is highly efficacious, using easily available starting materials under very mild conditions. Also the synthesis of some novel 5-substituted uracil derivatives 40 and 41 containing the benzoxazinyl moiety and of potential biological interest is being reported.     

5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮的合成

报道俘精酸酐类化合物(E/Z)4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2, 5-酮的拆分, 及(E)和(Z)-5-二氰亚甲基-4-二环丙亚甲基-3-[1-(2, 5-二甲基-3-呋喃基)亚乙基]四氢呋喃-2-酮 4(E)和4(Z)的合成, 并对它们的光致变色特性进行了初步研究。     

Allylation of Grignard Reagents: Its Application for the Synthesis of (4E, 7Z)-4,7-Tridecadienyl Acetate,A Sex Pheromone of Potato Tuberworm Moth

Alkylmagnesium halides have been found to react with (Z)-4-benzyloxy-1-chloro-2-butene in presence of HMPA to produce a rearranged product 3-alkyl-4-benzyloxy-1-butene, while in absence of HMPA a normal product (Z)-1-alkyl-4-benzyloxy-2-butene resulted as the predominant product. Latter product has been utilized for the synthesis of (4E, 7Z)-4,7-tridecadienyl acetate, a sex pheromone of potato tuberworm moth.     

Synthesis and oral activity of pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3(Z)- (4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylate (ME1207) and its related compound.

7-[2-(2-Aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3(Z)- (4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylic acid (11, ME1206) and its 3-trans isomer (13) were prepared to test antibacterial activity. These compounds exhibited excellent antibacterial activity against both gram-positive and gram-negative bacteria, including beta-lactamase producing strains. The pivaloyloxymethyl esters (12 and 14) of the compounds (11 and 13) were prepared by esterification with pivaloyloxymethyl iodide. Among them, pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]- 3(Z)-(4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylate (12, ME1207) showed good urinary recovery after oral administration in mice.     

Highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides from 1-bromo-1-fluoroalkenes via palladium-catalyzed carbonylation reactions

The highly stereoselective synthesis of (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated esters and (E)- and (Z)-alpha-fluoro-alpha,beta-unsaturated amides is described. 1-Bromo-1-fluoroalkenes (E/Z approximately 1:1), which are readily available starting materials, have been found to isomerize to high E/Z ratios after storage at -20 degrees C for 1 week or by photolysis at 254 nm. Since the (E)-isomers have been found to react faster than the corresponding (Z)-isomers at room temperature in Pd(0)-catalyzed reactions, the palladium-catalyzed carboalkoxylation of high E/Z 1-bromo-1-fluoroalkenes lead to a high Z/E (Z/E >/= 98:2) ratio of the alpha-fluoro-alpha,beta-unsaturated esters. When 1-bromo-1-fluoroalkenes (E/Z approximately 1:1) were reacted with HCOOH/NBu(3)/Pd(II)/DMF, the (E)-isomer was selectively reduced, and the remaining (Z)-1-bromo-1-fluoroalkenes were recovered in essentially pure isomeric form. The resulting mixture of (Z)-1-bromo-1-fluoroalkenes and the reduced products underwent similar palladium-catalyzed carboalkoxylation reactions at 70 degrees C, and the (E)-alpha-fluoro-alpha,beta-unsaturated esters were stereospecifically obtained. This methodology was also successfully applied for the stereospecific synthesis of (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides: the palladium-catalyzed carboamidation reaction of high E/Z and (Z)-1-bromo-1-fluoroalkenes lead to pure (Z)- and (E)-alpha-fluoro-alpha,beta-unsaturated amides, respectively.     

Parallel solution-phase synthesis of (Z)-3-(arylamino)-2,3-dehydroalanine derivatives and solid-phase synthesis of fused pyrimidones

N-Protected (Z)-3-(arylamino)-2,3-dehydroalanine esters 5 and 10 were prepared in one step from methyl (Z)-2-acylamino-3-(dimethylamino)prop-2-enoates 3 and 9 and anilines 4 employing a parallel solution-phase synthetic approach. In most cases, analytically pure products 5 and 10 were obtained. On the other hand, a three-step parallel solid-phase synthesis of 2-acetylamino-4H-azino[1,2-x]pyrimidin-4-ones 15 via the polymer-bound methyl (Z)-2-acetylamino-3-(dimethylamino)prop-2-enoate (12) was also developed.     

Synthesis of the N-((1E)-alkenyl)-(2Z,4Z)-heptadienamide side chain of salicylihalamide A and apicularens A and B

[reaction: see text] The unstable N-((1E)-alkenyl)-(2Z,4Z)-heptadienamide side chain of salicylihalamide A (1) and apicularens A and B (3 and 4) has been prepared in one pot by the addition of (1Z,3Z)-hexadienylcuprate, prepared in situ from EtLi, CuBr.SMe2, and acetylene, to a (1 E)-alkenyl isocyanate.     

4-{(Z)-[4-(Diethylamino)phenyldiazenyl]}phthalonitirle and Phthalocyanines Thereof

Russian Journal of General Chemistry - 4{(Z)-[4-(Diethylamino)phenyldiazenyl]}phthalonitrile was synthesized by diazotization and azo coupling and used to prepare...     

Simple and efficient production of (Z)-4-hydroxytamoxifen, a potent estrogen receptor modulator

A McMurry coupling reaction and selective crystallization were used to develop a simple and efficient two-step synthesis of (Z)-4-hydroxytamoxifen (2a). This compound is an active metabolite of tamoxifen, a selective estrogen receptor (ER) modulator widely used to treat breast cancer. The synthesis employed 1,1-bis(4-hydroxyphenyl)-2-phenylbut-1-ene (1) as a useful building block.     

(Z)-3-p-tolylsulfinylacrylonitriles as chiral dipolarophiles: reactions with diazoalkanes

[reaction: see text] The dipolarophilic reactivity of enantiopure (Z)-3-p-tolylsulfinylacrylonitriles (1) has been evaluated with diazoalkanes. 3-Cyanopyrazoles are obtained when R = H, but with R = alkyl (Bn, n-Bu, and t-Bu) only one cycloadduct (4 or 5) is formed in high yield under mild conditions, therefore evidencing a complete control of the regioselectivity and the endo/exo and pi-facial selectivities. These reactions are a new straightforward entry to the synthesis of pyrazolines and related structures and reveal the excellent dipolarophilic features of (Z)-sulfinylacrylonitriles.     

(Z)-3-丁烯基-4-羟基苯酞的合成

（Ｚ）－３－丁烯基－４－羟基苯酞的合成李绍白,王志伟,方小平,李裕林（兰州大学应用有机化学国家重点实验室,兰州,７３００００）关键词（Ｚ）－３－丁烯基－４－羟基苯酞,苯酞,３－丙基－５－羟基异香豆素,异香豆素,合成（Ｚ）－３－丁烯基－４－羟基苯酞（１...     

(E)- and (Z)-1-benzenesulfonyl-4-trimethylsilyl-2-butenes as (E)-1-(1,3-butadienyl) synthons

(E)- and (Z)-1-benzenesulfonyl-4-trimethylsilyl-2-butenes (E/Z=9), prepared from 4-trimethylsilyl-1-buten-3-ol, $\text{n}$-butyllithium and benzenesulfenyl chloride and oxidation of the intermediate (E)- and (Z)-1-benzenesulfinyl-4-trimethylsilyl-2-butenes with hydrogen peroxide, react with $\text{n}$-butyllithium and then primary halides to give 4-benzenesulfonyl-1-trimethylsilyl-2-alkenes which are rapidly 1,4-debenzenesulfonyltrimethylsilated to (E)-1,3-alkadienes by tetra-$\text{n}$-butylammonium fluoride at O°C.